How to press on right rear axle bearing w Hydraulic press

You have gotten good answers here. Sometimes it is hard to describe to others what you mean. To add a little clarification [I hope], there is either a center button or a center block inside the differential gears. The button or block floats about an eighth of an inch sideways, this allows both axles to move [push] against each other without putting pressure on the differential gears.

There are two different axle bearing retainers. A solid type and an adjustable type. They both push on the axle bearing [outer] cup. When both axles are assembled it is necessary to adjust the end play of the axle bearings. [about .010'']. With the adjuster backed off a few turns and the bolts tightened, the axle should have noticeable end play. Tighten the adjuster till the end play is correct. Check the end play again by hitting the adjuster side axle with a big hammer and a block of wood. This pushes the outer race against the other [solid] bearing retainer. Recheck end play and install the adjuster lock.