Any of the numerous of us out there whose door lock mechanisms have broken fixed it successfully themselves. Mines still under warranty but if it's a simple fix it would save a 300 mile trip to the dealer

 

Yes, I've done it and know that others have since I relied lots on their input (somewhere there is a thread on this topic with some good tips on how to do it). It is not that difficult, but requires patience, something to sit on that puts you about a foot off the ground (just the right height for working in the door cavity), and a good memory for how the cables are routed around the window track and motor (it took me three times to get it right, but that's not unusual for me when doing mechanical work).

Do a search on "door lock" and you'll find some good instructions.

Good luck!