mz6 or ms6?
the OTC 204-592 ball joint remover works.
and you only need to grind down the bottom two ball joints to make this work.
also i BELIEVE this one works too...
3/4" Forged Ball Point Joint Separator: http://www.harborfreight.com/3-4-qua...tor-99849.html
you may be able to muscle it, but honestly id be worried about causing dmg.
you should be able to use any press to push the stock ball joints out. just make sure when installing the new ball joints that they ar TQ'd correctly as failure with this part can really lead to some HUGE problems. quoted from 6club: "dont tighten the top nut until the ball joint is firmly level and has no tension on it. by tightening the bolt to bring the two pieces together u will fuck up the threads and have to get a new one"...
But sounds like your buddy is a shop guy so he probly knows what he is doin.
the one at harbor frieght is cheap enough to still be worth it even if you have to do some light grinding.
OR rent the full fledged one from Autozone/Pepboys/etc. return for full refund.