You need to find someone with a shop manual with that axle in it. Most of the later model rear axle assemblys use the same type of arangement. The pinion is set in two bearings, one at each end. The preload (adjustment) on the bearings is set by the pinion yoke and lock nut. You have to pull the yoke off to get to the seal. That part is pretty easy. The hard part is getting the bearings set back to proper torque. Some of the Dana type axles used shims between the bearings and you just have to tighten up the nut. The late model 10 and 12 bolt GM's have what is know as a CRUSH SLEEVE. Its ment to be compressed as the nut is tighten. Is very stiff and takes a lot of torque to compress it. Thats the tough part, pulling 200 foot pounds while trying not to go to much. If you go to tight, its trash and you have to get a new one and start again. Manuals list the inch pound force of rotation on the yoke. If you do them a lot you can tell by feel when its tight.

Find a manual and get after it. You will need a pipe wrench and big breaker bar, socket, and torque wrench. Joe

1937 Chevrolet Inline-powered Streetrod