Just took one apart that looked very similar

Had to pry off a cap on one side and punch out the pin, one side had a nail head appearance and the other the cap/ring retainer. If I were to do it over I would put down some tape right up against the cap and gently lift it off with an old pair of wire cutters.

I haven't tried to put it back yet as I am waiting on a new valve.

Good luck with it

James S