Like others have said the easiest and best way besides using a ball joint seperator fork is to use a good heavy hammer.

The bolt for the ball joint and the hole in the Lower Control Arm are tapered so that they are almost compressed together.

1. Loosen the nut enough so that there is a gap between it and the LCA and so that it is covering the end threads of the bolt so that if you slip with the hammer it won't F*** up the ball joint bolt.

2. Turn your steering wheel all the way to one side so that the LCA and Ball Joint are fully exposed. At this point it is optional to jack the rotor up an insch or two.... it won't help to get the ball joint out of the LCA but it will help you to see when it pops loose since it will drop more dramatically.

3. Finally just take a few good dead solid hits to the LCA knuckle where the ball joint is bolted up. Depending on how heavy your hammer is will determine how many solid hits it will take to pop it loose.