Oh FUN!!! this is what I was doing for 4 weeks on end without success until makka enlightenned me with the use of a ball joint splitter and a BFH...
BFH method: HIGHLY not recommended... it doesn't work most of the time and you really stuff up the screw threads. Read carefully: I HIGHLY recommend NOT doing this method! It cost me new steering tie rod ends cause the threads were FUBAR. (Could have been alot worse...)
Scissor type splitters: If using properly leverage on the top arm this method could work. Buy a good scissor type splitter (Expensive) and be careful... if you start screwing the scissors and it doesn't pop after a few heavy turns then it aint going to pop! you'll end up breaking the splitter tool (I did this twice! believe me!)
Fork type ball joint splitter and BFH: this method works a treat and the forks are cheap! $25 at any autobarn or autopro place (if they have them in stock, call first). Lever it correctly like above and bang away. The only thing and BIG thing you got to be careful about is to not dammage the balls themselves with the splitter. Do it with the dust protector on the ball joint or wrap the fork up in several layers of rags etc. But this method works best (couple of bangs and it's out)
It might be easier to split the bottom ball joint first before the top one... not sure but that's how we did it.
Is it a pot joint (clubby) shaft? if so you can either cut the pot joint boots off and pull out the shaft and catch the balls as they drop (6 in all) or drain the engine oil and use a pot joint remover tool (expensive) or some say you can use a tyre lever... either way it's too hard and detroying the boot is much easier... If any other type of joint like universal joint etc, then can't help you...
