[steamship]

Haven't replaced them, but a good start would be the following:

Repair group 60 in the following PDF: 28-Service Manual General body repairs exterior.pdf

Repair group 70.5 in the following PDF: 29-Service Manual General body repairs interior.pdf

Bear in mind that Audi tend to want everything removed to work on something, so it may not be absolutely necessary. I only had a quick look at them, but I didn't see anything specifically mentioning removal/replacement of the actual piping, but it does give information about the sunroof.

If you're replacing the front ones; part number 4E0877201; you're going to have to get access to the A-pillar, and the removal of some trim at the outer side of the footwell. Not sure how you'll get it past the dashboard, unless there's a decent gap for it. You'll also have to remove the rear half of the front wheel arch liners.

If you're replacing the rear ones; part number 4E0877203 (or 4E0877203A for LWB), you'll have to remove the trim at the side of the rear window, and possibly the trim for the curtain airbags. I believe they exit to the front of the rear wheel, so it'll either be loosen or remove that wheel arch liner.

When I was retrofitting the rear blind on the D3, I noticed that the drain pipe was made from a very soft plastic, so I'd say caution would be needed when fitting the new one, as I don't think it would take much to damage it i.e. I doubt you'll be able to feed it in one end and then pull it through if it's a snug fit.