rent the ball joint press from your local parts store.
mark a line at every thing you take apart, both at the rear diff and the u-joint yokes, so you put it back together the same way.
get heavy duty moog or precision brand replacemernt joints. don't get the cheap ****.
i prefer greasable joints over non-greaseable.
watch the videos on youtube to see how to press them apart and back in. i always remove each cap and smear a layer of grease around the needle bearings to keep them from falling out.
this is axle shaft u-joints, but lots of good ram info here.