My advice would be either to put a 1/2 ratchet on it and smack it with a dead blow hammer.

When I did my back brakes I actually had to cut 2 of the caliper bolts off with a sawzall and just went and got reman calipers... they were like 35 bucks at autozone with a lifetime warranty, it needed new calipers anyways.
Edit: buy all new caliper bolts that have a hex head on it instead of Torx... I believe all the new caliper bolts sold at parts stores have a hex head.

Don't know who's bright idea it was to use torx bolts there.

 

I had to use a large craftsman grip style clamp, 2ft 1/2" breaker bar and have someone hold the clamp to the bar and caliper, then break the torx free. I couldn't hold it in place and turn with enough force, just kept twisting out and even rounded the inside of the torx head some. After that, went to Napa and bought the "bolt style" replacement ones and got rid of Torx heads! Chris

 

I had a stuck one last week. I squirted it with penetrating fluid (Kroil) while working it with the impact wrench. I came back later and it broke loose with a breaker bar.

You can put a light coat of anti-seize near the head of the bolt, but don't get any near the rubber boot.

 

Heat the caliper casting, just under the bolt head, with a torch to about 200 degrees, and then retry with a torx socket. My torx socket (T55) is a 3/8" drive and I ain't broke one yet. Also, the top Torx does not need removed to remove the caliper.

 

Torch.

 

alright got new torx bit heated up reel good and finally got them out what a pain and stupid idea got new nut style from napa

heymccall thanks for all your acticles you have on d.p i have cleaned and greased my rear brears along with 4 new rotors and my truck stops like day one again