Control Arm Bushings

Yeah you need a separator tool like the above, or a pickle-fork (which requires the before-mentioned hammer swinging and is guaranteed to destroy the boot but is available in most auto parts stores whereas the nicer tool I haven't found locally -- I doubt a 40 year old boot is in very good shape, mine were dry-rotted even though the joints were good). Definitely don't try to bang or pry on the arm itself, you'll damage it and it won't work. Hitting the threaded part of the joint will destroy it as well. Sometimes a few sharp hammer blows to the spindle (the cast iron part, on the side, where the ball-joint goes through) will cause the joint to pop loose - works on tie-rods too.

Oh, and be sure you have a jack under the lower control arm and that the shock is still in place. Otherwise you might be catching a spindle upside the head when it does come loose.

i hit the spindle beside the ball joint and it comes apart everytime. i ordered all the bushings and ball joints off ebay for around 100$ and it was the same brand the parts store had but a whole lot cheaper