Richard,
Somewhere in my vast collection of stuff are the two "arms" I made to fit in the slots of that inner retainer. I can't find them, but I do remember that I used a large pair of channel locks (Craftsman) to persuade the ring to compress, both coming out and going in.
A correction, the formed spacers (C5ZZ-15251-A) I have are clear zinc plated, not painted argent.
Jim