It is that difficult, I've replaced mine twice now due to a faulty tensioner, and my buddy has a 2.8. Same problems just gatta take off the entire front end. The part your probably lookin for is 5040338 if I'm right and it only costs 15.49 at advanced auto parts. I'm not sure if that's the part because idk the year, but I'm pretty sure they're universal for 1.8t b5 a4s.

 

well I took it to the garage and paid £150.00 for a belt, tensioner, labour and VAT.

Once again thanks for all the info as usual it was right on the money.