I had the same problem with my drivers side door and decided to sort it out over the weekend- got the door lock for 62.60 + VAT (Euro) from Audi and borrowed a friends garage....it took about 2-3 hours and was easy enough to do although there were a few heart in mouth moments when i wondered if i'd gone too far....i took some photos along the way which i will post soon....basically i went about it like this- I put window fully down, then i took off door card (screw on top left and right of door and two behind handle grab (remove screw to see these)- then lifted door card upwards and off the door- then disconnected all the electrics (block connectors- some stubborn!)...then undid four big hex bolts on subframe (at this stage as someone suggested previously I noted the position of the spacers at the hex bolts) and once all the bolts were off I swung the door frame (which includes window frame and mirror) away from the door....then I removed a plastic shield in front of the lock and disconnected rods, electrics, door pin at lock unit and undid two smaller hex bolts to free the lock assembly (these bolts are located at side of door- visible when door open)....switched the door lock and put it all back together....door lined up perfectly and everything is working as new....(I'm not saying this is the way to go about this job- there may well be an easier way but the method described above worked for me and it wasn't hard to do!)....