I had a long telephone call last night from a fellow that owns these and a site member and he set me straight on how to do it. The one thing I did not realize was that the breach of the receiver is spring loaded and slides back and forward, so one needs to apply pressure to the brach with the bbls when you are depressing the pivot stud in order to get enough room to mate the parts into the slots made for each of the pivot and the extractor. That was the trick.

Thank you to those who helped.