First spray the lug section where the center of the rotor makes contact with hub with WD40 or any nut buster spray. Let it sit for a while and spray again. The longer you wait and more you spray the better. Some times it will come loose by whacking the rotor with a small sledge hammer (don't be afraid to hit it good). Just don't hit the pad surface unless you plan on replacing the rotors. You can hit it on the outer edge from the sides. Hit it and rotate the rotor and hit it in different spots. If that don't work use the threaded bolts (make sure they are the right size and there is enough thread on the bolt so that the bolt can push the rotor off, no shoulder, a hardened bolt is best) in the threaded holes in the rotor (there is usually two, you may want to put a little never seize on the bolt thread). If you have or can get an impact gun, use it to tighten the bolts without having to worry about holding the rotor, to keep it from turning. You must tighten the bolts a little at a time, tighten one a little then tighten the other. DO NOT TIGHTEN ONE ALL THE WAY DOWN. Go back and forth between the bolts. If you don't have an impact gun use a breaker bar or ratchet with some type of extended handle or put a pipe on it to get better leverage. Be careful not break the bolt because of a bad angle. To keep the rotor from moving you can wedge a crow bar or tire iron between the lugs and the ground (wrap the bar or iron with a rag so you don't damage the threads). Try not jerk the breaker bar, apple smooth pressure so the crow bar doesn't fall off. If possible, hit the rotor with the hammer as you are tightening the bolts (an extra hand would be a good idea). On the front rotors, you can also wedge the crow bar between the lugs and part of the suspension by turning the wheel all the way to the right or left.
Good Luck!
Koz
