I have water inside a shower bench made of cultured marble. Request instructions on removing and reinstalling shower bench seat. Also damage inspection parameters, please.
Depends a lot on how it was put together...this sort of thing is likely custom, so there's no common way to do it.
If you can see the ends and they're caulked, you could try digging out all of the caulk. Along the edges, maybe a utility knife to cut it and then see if you can lift it up. Once you've got it loose, you can assess what is going to have to be done to fix it. If you pry too much, you'll possibly crack or gouge it. A putty knife might be useful too, to try to get it unseated. If they used a glue other than something like an acrylic caulk, it could be a real bear getting it loose.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013