Power Window jammed

Hello D Gurus,
Rear left side (driver side) power window jammed on my D yesterday. When I push or pull the power window button, I can hear a humming noise and the window quivers a little which led me to believe that the motor may be fine and probably the fuse too. Any ideas on how to fix it or what may be wrong from the symptoms? I'm mechanically illiterate.

Thanks

pull the door panel off, check for worn or broken off teeth on the gear that the motor turns and the motor itself. If you find no problems there check the clutch.