What is the minimum parts you need to swap from a 7.5 rear axle to a 8.8 rear axle for purposes of installing a locker from ox-usa.com ?
(Since the ox is going in place of the open-diff, I assume you don't need the entire open-diff rear axle assembly, since you will be removing most of it anyway.)
For reference, this regards a 2wd 2001 Ford Ranger.
Apologies in advance if this is a dumb question.

 

4 new U-bolts for the attachment to the leaf springs, its possible to use the old ones but the threads can be pretty bad and new ones are not expensive

A gasket for differential cover, factory just used RTV and no gasket and you can do the same, up to you really

You can install new axle bearings and seals since axles can be pull out once spider gears are out, but a judgement call if there are no signs of leaking now
This is one of those PITA parts to change after the fact, so look at the cost of bearings and seals, not hard to do so its strictly a cost decision

Rear brakes...................