I had read here that installing a lift via removing the lower ball-joint mount that it would be difficult to compress the upper A-arm/spindle back to the lower control-arm. I installed my lift and was expecting this to be the case, and it was the case.
Tip: I used a heavy-duty ratchet strap. I made a loop with the strap around the upper and lower control-arm, connecting the two strap hooks together. Then I ratcheted the upper and lower control-arms together and easily bolted the ball-joint mount to the spindle.