[Hocrest]

I think it's a 35mm socket to remove the staked nut at the back of the pinion shaft.

Be careful when dis-assembling the back of the pinion shaft, the parking pawl and the gear it engages is held there and you need to take note of how it gets reassembled.

Keep track of the shims around the bearing plate at the front of the pinion shaft

Replace the oil seals on the bearing plate