The tapered joints of the balljoint are pulled into the spindle with 100 ft/lbs of torque. These joints are tight! To remove or replace parts, some recommend putting a pickle fork tool between the ball joint and hit it with the biggest hammer you can find. I was concerned this would destroy the rubber boot that surrounds the balljoint. A jacking screw generates the necessary forces to safely take the joint apart without destroying anything.
I made the screw using a 3″ piece of 1/2-13 threaded rod and two coupling nuts. I cut a couple 1/4″ pieces of the rod and threaded them into the end of the coupling nut. This would close the end and give a surface to bear on. I assembled the ends with blue Loctite.
I loosened the castellated nut on the lower joint, backing it off the spacer about 1/8″. I then placed the jacking screw between the two stud ends and tightened the coupling nut. In a couple turns, the tapered stud was easily pushed out of the spindle. I then loosened the upper nut and repeated the process.