I had a problem with the driver's door window which stuck, partway and would not move, up, or down (it failed to proceed). I was advised by other members that it could be for one of several things, most likely the motor. So I decided to investigate, and share the outcome. This may be of interest to some members with similar problems. For access, the internal door panel had to come off, and I proceeded as follows.
Firstly I had to take the door handle off, by removing the two screws from under (8 mm socket), then disconnect the lamp-holder and store handle safely. Using wood or plastic, I had to prise the plate from behind the door handle and window switch exposing the fixings, then I had to take out two screws from the bottom of the door storage compartment, then take out screws from the bottom of the door. These were hidden by carpet (mine had four screws).
I had to gently prise away clips (10 in number) to release trim surround, and drop it from under the wood door capping exposing 3 screws. These were removed and I could take off the door covering and plastic dust cover which exposed the mechanism and motor. I had to release the motor and drive box, by taking out three awkward bolts, making sure to collect three spacers, and six washers. With the unit on the bench, I separated the motor and drive box, exposing the plastic drive-link, this is where my problem was. The link had broken up, jamming the mechanism. I tested the motor, which was ok so I purchased a new link from Flying Spares. I cannot remember the exact price, but it was around £6.00.
I thoroughly cleaned out the old link and debris, fitted the new link and fitted the assembly together, I retested everything before reassembly. I used some tape to hold the washers and spacers in place to aid reassembly. Perhaps another way to take out the assembly would be to access the mounting bracket through two rubber bungs at the bottom of the door. Reassembly was the reverse of dismantling. I think I found realigning the 10 press clips the most frustrating, but the result is very satisfying now it is all working again. Obviously, the problem could have been a faulty switch, micro switch, blown fuse, poor connection, faulty motor etc. but you don't know until you investigate, eliminating easiest items first.