The shaft should be balanced individually is my understanding, and I've always had them do it that way when I've had shafts made. I'm a bit OCD these days and put them back how I found them, but also strip and paint them. In any event, I've never had vibration issues installing them opposite how they came apart or mixing and matching shafts.
Did my rear shaft this week. I cut the old carrier bearing off. Cutoff wheel most of it and chisel and 4 lbs hammer to break it, then tap it off with the chisel. This one sucked to do, often times they'll come off each with a little heat and an air chisel and just walks off. Not this time for me, but I always try that first. Other methods include a bearing plate/clamp for removing bearings in a press. My press won't fit a driveshaft, but I've used the bearing puller clamp before and either been able to brace that and tap the shaft out with a hammer and punch or block of wood or with a piece of angle or square tubing with holes and bolts to hold the end of the shaft and pull the bearing off. Air chisel and if that fails cutoff wheel is pretty much quickest for me though.
To install the new you need a piece of pipe or tuning that fits around the shaft tightly enough to only touch the inside race of the bearing, do not pound on the outer race or you'll damage the bearing. Just tap it on. If you don't have that handy you can use an appropriate sized punch or small drift and work your way around the bearing, hitting only the inner race.
Turns out he did not seat the rear joint in the differential yoke. I fixed that for him..
