Coping/stabiliser rust

I have a 24’ round Trevi AG pool. Liner was replaced last season by a pool repair person. There are 17 segments of Wall. 7 of them have metal coping and 10 have plastic. The metal coping is rusting and breaking into pieces and falling into the pool. Can I replace the metal sections with plastic or is there a reason some of them are metal? If I replace one section at a time while the pool is full will The liner slip and prevent me from getting it put back together?

The installer won’t return my calls and nobody else in my area works on AG pools so I’m on my own.

Thank you!!!

You can replace the metal coping with plastic if there is a plastic equivalent available. Unfortunately, we do not sell Trevi parts. We recommend trying http://www.loceypool.com/poolparts.php.