[Yo-Yo]

Two hardest pins to install: Bolt Latch roll pin, and trigger guard roll pin.

The rest of the assembly is a piece of cake.

[The Pack Knight]

Yes! I have yet to drive one in without marring the finish on the lower.

[real saxophonist]

That's when you need a roll pin punch of the right size, and one of these:

And a carpeted table so you don't lose anything.

[Charles Martel]

Two hardest pins to install: Bolt Latch roll pin, and trigger guard roll pin.

Lots of lowers now have a full trigger guard already cast in place. For those that still have the original style casting "ears", the MagPul trigger guards can be installed with screws - no worries of breaking off a mounting ear when tapping in the roll pin.

[Billthedrill]

Two hardest pins to install: Bolt Latch roll pin, and trigger guard roll pin.

Yup. What you might try - I do it this way now - is using a roll pin starter punch and then a pair of channel-lock pliers to squeeze it in instead of "tapping" with a hammer. (Tapping my butt, I had to pound my first one like fiend. Lubrication helps.)