we had that same issue here on a 90 xj. it toook us about 8 hours & we ended up breaking a few parts( the knuckle cracked & the wheel bearing split). lots & lots o pb blaster like rob said & tap it with a few choice words ( talk dirty to it). & just remember you can always find dana 30's all over the place.

93 xj stroked 4.2 w/4.0 head avenger supercharged 6.5" long arm 35" buckshots rubicon 44's front & rear