OK, I'll play along for a minute.
Here's is the bulk of the OT law regarding the keeping of the Passover:
Now the Lord spoke to Moses and Aaron in the land of Egypt, saying, "This month shall be your beginning of months; it shall be the first month of the year to you. Speak to all the congregation of Israel, saying: 'On the tenth day of this month every man shall take for himself a lamb, according to the house of his father, a lamb for a household. And if the household is too small for the lamb, let him and his neighbor next to his house take it according to the number of the persons; according to each man's need you shall make your count for the lamb. Your lamb shall be without blemish, a male of the first year. You may take it from the sheep or from the goats. Now you shall keep it until the fourteenth day of the same month. Then the whole assembly of the congregation of Israel shall kill it at twilight. And they shall take some of the blood and put it on the two doorposts and on the lintel of the houses where they eat it. Then they shall eat the flesh on that night; roasted in fire, with unleavened bread and with bitter herbs they shall eat it. Do not eat it raw, nor boiled at all with water, but roasted in fire--its head with its legs and its entrails. You shall let none of it remain until morning, and what remains of it until morning you shall burn with fire. And thus you shall eat it: with a belt on your waist, your sandals on your feet, and your staff in your hand. So you shall eat it in haste. It is the Lord's Passover. For I will pass through the land of Egypt on that night, and will strike all the firstborn in the land of Egypt, both man and beast; and against all the gods of Egypt I will execute judgment: I am the Lord. Now the blood shall be a sign for you on the houses where you are. And when I see the blood, I will pass over you; and the plague shall not be on you to destroy you when I strike the land of Egypt. So this day shall be to you a memorial; and you shall keep it as a feast to the Lord throughout your generations. You shall keep it as a feast by an everlasting ordinance. Seven days you shall eat unleavened bread. On the first day you shall remove leaven from your houses. For whoever eats leavened bread from the first day until the seventh day, that person shall be cut off from Israel. On the first day there shall be a holy convocation, and on the seventh day there shall be a holy convocation for you. No manner of work shall be done on them; but that which everyone must eat--that only may be prepared by you. So you shall observe the Feast of Unleavened Bread, for on this same day I will have brought your armies out of the land of Egypt. Therefore you shall observe this day throughout your generations as an everlasting ordinance. In the first month, on the fourteenth day of the month at evening, you shall eat unleavened bread, until the twenty-first day of the month at evening. For seven days no leaven shall be found in your houses, since whoever eats what is leavened, that same person shall be cut off from the congregation of Israel, whether he is a stranger or a native of the land. You shall eat nothing leavened; in all your dwellings you shall eat unleavened bread.' " (Exo. 12)(Feel free to add anything I have missed.)"You shall not offer the blood of My sacrifice with leaven, nor shall the sacrifice of the Feast of the Passover be left until morning." (Exo. 34)
"'These are the feasts of the Lord, holy convocations which you shall proclaim at their appointed times. On the fourteenth day of the first month at twilight is the Lord's Passover. And on the fifteenth day of the same month is the Feast of Unleavened Bread to the Lord; seven days you must eat unleavened bread. On the first day you shall have a holy convocation; you shall do no customary work on it. But you shall offer an offering made by fire to the Lord for seven days. The seventh day shall be a holy convocation; you shall do no customary work on it.' " (Lev. 23)
Now, tell us plainly, while carefully observing all the "jots and tittles" and "least of these commandments" (Matt. 5:18,19), how does one observe this "passover" today?
Under the new covenant, we observe Passover as God in the flesh observed it and as his disciples observed it. We follow the example set forth in scripture:
1Jo 2:6 He that saith he abideth in him ought himself also so to walk, even as he walked.
1Co 11:1 Be ye followers of me, even as I also am of Christ.
How did Christ observe Passover?
Lev 23:5 In the fourteenth day of the first month at even is the LORD's passover.
Mat 26:26 And as they were eating, Jesus took bread, and blessed it, and broke it, and gave it to the disciples, and said, Take, eat; this is my body.
Mat 26:27 And he took the cup, and gave thanks, and gave it to them, saying, Drink ye all of it;
Mat 26:28 For this is my blood of the new testament, which is shed for many for the remission of sins.
We know that Paul, an imitator or Christ, did the same thing:
1Co 11:23 For I have received of the Lord that which also I delivered unto you, That the Lord Jesus the same night in which he was betrayed took bread:
1Co 11:24 And when he had given thanks, he broke it, and said, Take, eat: this is my body, which is broken for you: this do in remembrance of me.
1Co 11:25 After the same manner also he took the cup, when he had supped, saying, This cup is the new testament in my blood: this do ye, as oft as ye drink it, in remembrance of me.
1Co 11:26 For as often as ye eat this bread, and drink this cup, ye do show the Lord's death till he come.
Jesus, God in the flesh, also gave another command to be observed at Passover under the new covenant:
Joh 13:12 So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, Know ye what I have done to you?
Joh 13:13 Ye call me Master and Lord: and ye say well; for so I am.
Joh 13:14 If I then, your Lord and Master, have washed your feet; ye also ought to wash one another's feet.
Joh 13:15 For I have given you an example, that ye should do as I have done to you.
As far as the animal sacrifices you listed, the new testament clearly teaches that under the new covenant Christ is the sacrifice:
1Co 5:7 Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us
Heb 9:9 Which was a figure for the time then present, in which were offered both gifts and sacrifices, that could not make him that did the service perfect, as pertaining to the conscience;
Heb 9:10 Which stood only in meats and drinks, and divers washings, and carnal ordinances, imposed on them until the time of reformation.
Heb 9:11 But Christ being come a high priest of good things to come, by a greater and more perfect tabernacle, not made with hands, that is to say, not of this building;
Heb 9:12 Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us.
Heb 9:13 For if the blood of bulls and of goats, and the ashes of a heifer sprinkling the unclean, sanctifieth to the purifying of the flesh:
Heb 9:14 How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?
Heb 9:15 And for this cause he is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance.
Now do I observe the Passover perfectly? Not by any means. I also don't observe the sabbath perfectly. In fact, I don't observe any commandment perfectly. But that doesn't mean you throw you your hands and say "I can't do it". It means that you submit yourself to the will of Christ, living in you, and overcome, build TOWARD perfection by letting his spirit work through you:
Heb 13:20 Now the God of peace, that brought again from the dead our Lord Jesus, that great shepherd of the sheep, through the blood of the everlasting covenant,
Heb 13:21 Make you perfect in every good work to do his will, working in you that which is wellpleasing in his sight, through Jesus Christ; to whom be glory forever and ever. Amen.
These are the feasts of the Lord, holy convocations which you shall proclaim at their appointed times. On the fourteenth day of the first month at twilight is the Lord's Passover. And on the fifteenth day of the same month is the Feast of Unleavened Bread to the Lord; seven days you must eat unleavened bread. On the first day you shall have a holy convocation; you shall do no customary work on it. But you shall offer an offering made by fire to the Lord for seven days. The seventh day shall be a holy convocation; you shall do no customary work on it.' " (Lev. 23)
There is a biblical distinction between Passover and the days of unleavened bread, but if you would like me to tell you how to observe that festival I will be glad to share.