Tool? There is no tool that I'm aware of. just screw the bolts in the other side and they hit the housing, I braced it with steel to avoid screwing anything up.
You are talking about having troubles getting the hubs out right? Soak, soak, and re-soak with pb blaster... Mine came appart hard but finally came out. The ball joints where a pain! 1 broken ball joint press and 2 cans of pb blaster later, they finally all popped...
Why are you removing the ball joints to install a locker?
My bearings came out pretty hard too but not too bad, I have had to replace others that we torched out, beat, etc. Sometimes what I do is run a chisel in between the bearing and the break disc cover, and hammer the heck out of it and then it comes out pretty good but ruins the dust cover. But i order a new cover and were good to go.
what brand locker are you putting in and where did you get it from?