We've heard that ball joints should be pressed out. The ball joints actually screw into the upper A-arm and removal requires a special square-drive socket and lots of torque. We had the special socket for the larger B-, E-, and late A-Body ball joint, but had to make one for the small A-Body piece. Starting with heavy wall pipe, the drive flats were arc-welded in, precision cut to size, case hardened, and quenched. Heat the A-arm frequently with a torch around the ball joint and then lightly oil to break the joint loose-ours required that treatment.