RV Repair: Shower surround, paneling, wallboard

Question
The wallboard in our shower (upper corner and part of ceiling) has pulled away.  Can this section be replaced or do we need to do the whole surround, and can we do it ourselves? This part of the ceiling is curved.

Answer
Without looking at it, it is hard to say. What is it made of? Fiberglass, vinyl-coated paneling, plastic?
You say it is curved, which makes me think it is probably fiberglass or plastic. It is hard to bend paneling.
If it is just paneling, it should be easy to just replace the damaged parts only.
I don't know if this helps you much.
Ask a followup with more info if you would like.
Thanks,
Dave