733I sunroof liner removal

I'll try to be more specific this time. I have an 84 733i. The sunroof
has been leaking for some time before I got the car and the drive mechanism
is all seized up. All I can do manually is to raise the roof, not slide it
back, and even that is getting harder, soon to be impossible. The motor has
already burned up so using it to do anything is fruitless. If I get the
sunroof liner off I can remove the ceiling headliner in front of the
sunroof, which will allow me to remove and replace the motor. If I can get
the sunroof liner off I can start removing the main headliner so I can get
the entire sunroof assembly out. I need to know how to remove the sunroof
liner, hopefully without destroying it in the process.