Will's method is the one I'm most familiar with also. It might be obvious, but vise-grips come in really handy too. If the bolt or screw strips out but the peg is partially out, try grabbing it with vice-grips (really hard) and twisting back and forth a little while someone uses a pry bar under the head of the vice-grips. I like using a small "wizard" bar because the lift is straighter.

Rudy