767 Jockey Doug First off, get a 6 sided extra long wrench. Get a small hammer and tap on the location as close to the mounting point as possible. You are trying to SHOCK the bolt from the threads. If you can get 1 bolt out, you can spin the calpier assembly a little to loosen the other bolt. A little heat doesn't hurt either, just becareful not to have brake fluid come out of the caliper and catch on fire.
I have seen this happen. NO, not me.
Rick L.