About 15 years ago just about all of the suppliers sold a reproduction roller bearing race that was just terrible. Besides being made of poor quality material, it did not have the important dimple to lock it in place. Bratton's finally had a correct race made and several other suppliers followed. However, probably hundreds or thousands got out into the world, and some suppliers probably still sell them.
To answer your question on how to: Go to the web site of the Santa Anita A's of Arcadia,California at
www.santaanitaas.org. On the home page put your cursor on "Technical Reference", my name will drop down below, click on it. It will bring up a technical library. Scroll to the differential section and you will find numerous articles that should answer any question you have about the rear axle assembly. They are all PDF files and you are welcome to download any of them.
Tom Endy