Identifying and adjusting Bilsteins on my 2001 S4

[aagallarini]

I've recently aqcuired a 2001 S4 from a guy that told me the Bilsteins on the car were adjustable. I don't know for sure that they are, but he seemed to think they were after I asked about them. I guess he checked with a friend or something. It's also got Eibach springs. I want to remove the wheels to see what identifying numbers I can find, but want to make sure I'm looking in the right place.

Can anyone give me some ideas about what to look for?