One thing I have found that seriously does help is some good penetrating oil. Spray some on and let it sit for a good 30 minutes.
I just replaced the rear rotors, one of the calipers and the pads on the wife's Taurus the other day and that same gorilla that must work at every manufacturer sure enough torqued the caliper mounting bracket bolts to a zilliony billion ft/lbs
I have an impact wrench but in most cases I just use a long 1/2" drive breaker bar with the air sockets and a dead blow mallet. May not work if you don't have the room but like I said, with penetrating oil the breaker bar works for me in "most" cases....