the sunroof won't open or close

This is a tuff job,you will have to remove headliner to get to it,and this is a job unless you have some mechanical skill,but it sound,s like the cable has twisted up that pull,s and pushes the sunroof.

Before removing the whole frame, it's worthwhile to try operating the roof with the little manual handle that's stored next to the sunroof motor. It's possible that the motor is weak or its teeth are ground off. Otherwise, it'll be the whole assembly as TST4 said.