I've taken pretty much everything off that's required for a timing belt change but I can't get the viscous fan off (pictured) to get to the water pump and to take the old timing belt off... Any ideas?

 

First thing you need to know is that the nut behind the fan is reverse threaded (lefty tighty, righty loosey).

Second, there are special audi tools for the removal of the fan pulley. A funky looking wrench and the dreaded "chopsticks" tool, I don't remember the tool numbers off the top of my head. The chopsticks holds the pulley by the small holes, and the wrench is obviously for the nut. Of course, you can improvise. Personally I used a large open end wrench for the nut and I used some tensioned webbing wrapped around the frame rail to hold the pulley. Mine was on pretty tight though and it took a great deal of force to break it loose. I've seen a couple other write ups with other ways to improvise the removal (channel locks) but you have to be careful not to damage anything.

good luck. keep us updated with your progress