Alec: Have you knocked out the little retaining clips on the inside of the ears? If so, have you tried placing the axle shaft ear on a large diameter socket and hitting the other side of the u-joint with a brass drift. Heating it with a torch is another option. Also, as long as your doing this replace the u-joints with the NAPA super strength ones. IMHO they're worth the extra money, especially if your running a front locker. Hope this helps.
Shain
Shain