Other method
Copy Move parts wanted to change
Separate
Hidden Function: ShrinkTrimmedSrf (Press Tab and write ShrinkTrimmedSrf )
Add pointsif necessary and move them as you want...

PS You can make the same directly on the ring! (so don't need to Move)
-just separate Up Down faces !
Here the separate move


Here directly on the ring!
Select All Separate
Select the 4 little parts
Show Points
ShrinkTrimmedSrf
etc