How do I go about removing the door panels in a 1991 420 SEL?

When I open the drivers side window the door panel bulges out for a second and there is a slight rattle in the door. Any ideas before I open it up?

the normal way
 

Just unscrew the lock button from top, remove all handles (Phillips screws), gently remove from door careful not to break pins around door trim and you should have it :).
Is your window electric? If so maybe the motor has come loose my rear window on my wagon had simmilar problem and I had to replace the winding mechanism worn out, pain in the bum :( to do , be careful can be sharp if worn or maybe motor needs replacing . Good luck ;-)
regards
BB W123 wagon