Sorry Tusabes, I don't check the Forum every day. The instructions contain links so to simplify I will just list them. I am assuming front door.
1. Pry off the small speaker grill and access Philips screws underneath to remove triangular plastic trim.
2. Remove two Philips under wood cap and lift wood cap up and off. If the glass is stuck closed you will need to work the wood a little.
3. Pry off cover plate on door latch and remove 2 screws securing latch trim. Remove trim.
4. Remove 2 10mm bolts underneath armrest and remove armrest.
5. Starting at bottom of door, work a pry between trim panel and door to release push-pins. There is a special notched tool for this but not essential. Inevitably some pins will break.
6. Once all pins are released lift trim panel up to release top bracket. You will then need to separate all electrical connectors to remove panel completely.
If it is a rear door instructions are the same except instead of removing triangular plastic trim you must remove the vertical plastic trim separating the window from the quarter panel. Pry it loose from the top and then lift.
It is unlikely the motor is bad. More likely cable problems or glass is simply jammed. Check power to motor first.