A piece of advice that I found that worked really well for me was to take a tow hitch and put it against the flywheel with the ball end of the hitch sticking up, then take a pair of blue handle old school channel locks and put the ends of the handle over the stainless collar in your photos, then take a medium sized zip tie and put it around the end of the channel locks after you slide the ends of the handle over the collar. It’s even easier if you take a pry bar and put that against thr tow hitch then use the tips of the channel lock handles sticking out an or so from zip tie to pry against the collar in order to slide it bank and get the O ring out. The Channel locks work great because they can push on 2 sides of the collar at once which is the “trick” to thr carbon seals. I did both sides off and on by myself using this method.
DZ