I didnt know squat about getting in there, but I was able to get in to change the gears. There should be a sticky on the gears...follow the same for the motor.
RC
I had a window motor problem too: No odd noises, just that my window would not roll up all the way or down all the way. Motor was find I figured cause it made no unusual noises. Turned out all I needed was the bushings (3 plastic/wax parts).
I printed out the instructions from the sticky on this forum and got the bushings replaced in under an hour. Took my time and it worked out very well.
Now that I think of it, I'm probably going to replace the bushings on the other window since it is most likely very worn after 13 years now.