hah, mine were the same way, i wanted to inspect the rotors, so i tried to take them off...DENIED! i POUNDED, HIT, SLAMMED, YELLED, SWORE, BANGED, THREW, SHOT, TORCHED, and tghey just sat there and looked at me sayin, hey, look at that dumbass...

I spray it with a good penetrant like PB Blaster, and then use a hammer striking between the lugs. Extra care has to be used not to hit the lugs and mess up the threads. I've had some stubborn ones, but they've all come off eventually.