Chryco, I have found two techniques to have some success where the ball joint stud is spinning in the spindle hole; the first is to compress the spindle against the ball joint, with a monster pair of channel locks, and a burly friend. This will often get that seized nut removed. The second is a little more violent, and a little more desperate: hammer a pickle fork into the space between the ball joint and the spindle, and then try to turn the nut off. Good luck, and you might wind up splitting the nut. As for the original problem of the stubborn removal, it is just a matter of rust penetrant, patience, and lots of brute force. They do make tools for pressing studs out of their attachment points, but this also presents some problems. Sometimes, the parts do not want to come apart, and you will break the tool.