You're going to have a tough time. The sabbath isn't a ceremonial law, but is a moral, eternal law because it was created holy in the beginning:
Gen 2:1 Thus the heavens and the earth were finished, and all the host of them.
Gen 2:2 And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made.
Gen 2:3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made.
If you're going to rely strictly on scripture you can only come away with the conclusion that the sabbath was never made "unholy". Jesus Christ, the Lord, never changed HIS sabbath. However if you want to make your case based on culture, history and human reasoning you'll have a much easier time.