Just finished replacing the driver side front door latch on my 03 A6 3.0. With very few write-ups on how to this I found it very easy. Except for actually getting the latch out. My problem was figuring out how to get the tumbler out of the latch so that the latch could be removed. I ended up breaking the the retainer on the tumber, which in turn released the parts including the spring from inside the tumbler. So, I was able to remove the latch, which was nice. It took me awhile to replace the spring back inside the tumbler and using some generic retainer to hold it in place.

All said and done I should have removed the door handle prior to breaking the tumbler this would have solved a lot of problems. So follow the other write ups on this procedure, but remember to remove the door handle it would make things a lot easier.