The lower unit leaks so I am replacing the seals. On this model, I am having difficulty figuring out how to replace this seal on this piece (see attached photo).
Before I start beating on it with a 5 pounder, I thought I would ask first. Does this thing come apart? How?
Right behind the o-ring where the metal is of a different color you need to separate the two pieces at that point. I would try working a razor blade into that junction or maybe a putty knife or some thin object to get that joint to separate.
Those things also had two different size seals that may be in them the outside diameter is close but not quite the same using the wrong one in either application will cause leakage. Found this out the hard way on a fresh painted lower unit. So measure and confirm that the old one is relatively close to the new one.