I replaced the ball joint 2 weeks ago. I remove the tire to get more access, I didn't remove the caliper assembly(because I didn't have to). don't lose the bolts that secure the ball joint to the control arm, you have to do it after remove the bolt that secure the ball joint to the stering nuckle. Once you lose the bolt try to move the control arm up and down while you unscrew.If this still not working then try using a large flat head screwdriver between the union that sucure the ball joint in the steering nuckle. Once you remove the ball joint fron the nuckle you can take off the bolts that secure the ball joint from the control arm.