Herb, here's what I'm seeing in my parts manual. There are two "lock rings." Item number 12 and 20, for the top and bottom of the" ring pack support" #17. Additionally, at the bottom of the collar is a snap ring item #21, listed as "ring-retaining." I've removed item 21, but that was easy to see and access. So which internal ring am I missing because I don't see how to remove 12 or 20 until after removing the lower strut....in fact the book says to remove 12 and 20 after removing lower strut from the upper strut.