Boosty is right, perservance does pay off. One of my troubles was that is was difficult to get a good straight hit on the locking ring. I had been trying to use my brass punch, to eliminate the chance for sparks, but it didn't engage the ring very well. I resorted to a good old fashioned flat blade screwdriver and was able to persuade it to turn.
After that the replacement was actually anticlimatic. And the good news is that it runs again!!!!
I'll have to save that character building exercise until I have to do the same thing to my Bonne!
Thanks to all for the input and feedback.