I had some of these on my former mobilvetta motorhome, the aluminium bezel normally twists off from the main body
The spotlight I’m not sure but I’m sure that someone on the forum will offer advice
i am sure the bezel on the spotlight will unscrew aswell - some of the bezels on the larger ones (as shown on your pics) just twist a little as they have lugs on them as opposed to threads the smaller ones are likely to have threads on the bezel
From memory I think that mrb1959 is correct in that the bezels do have a couple of lugs that catch on the rim rather than a full screw type fixing, jus turn them about a quarter turn and they should fall off