If they are like mine on my o4 MA gasser (98-02 Mercury Marquis) they are one piece and can not be taken apart. They are also mounted kind of weird.
I had a bulb reflector cover fall off and Newmar replace the whole headlight.
I had to figure out how to R&R the headlight. Here is photo of a mounting post.
Here is the backside of the headlight bucket and 3 of the mounts.
Here is a closeup of the mounting retainer.
You have to release the little caches on the retainer clip and the pull the retaining clip loose on all the mounting point to remove the headlight.