You could take a bunch of digital pictures of it before you dissassemble it.

If you don't have a digital camera, you can draw a sketch of what goes where, and write down which pieces connect at what an angle.

Look for those plastic parts and for broken bits of plastic in the bottom of the door. If you find broken plastic, that's a regulator problem. Replace those parts, taking as few pieces apart as you can.

If the motor is binding, it will be binding at some particular joint. You might turn on the ignition and fiddle a bit with the window switch and check to see what it it trying to move.

Remember Right is tight and left is loose.
Righty-Tighty, Lefty Loosey

And good luck.

__________________
Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)