I have a method where I put a little pressure on the drum with Large Craftsman screwdrivers jammed between the drum and the housing, (like Jerry says) THEN and most importantly...
Screw on 3 lug nuts across from each other. Screw them in such that you have the lug nut just barely sticking out further than the stud. Use a hammer to wrap the lug nuts until it breaks free. You shouldn't be a gorilla about it, just wrap them and see if that doesn't solve the problem.
