I replaced mine last year. I took the instrument oval out. Carefully unplugged it, took out the old led and put in the new one. I bought it on Ebay , I think. $125.00. If you will Google it, you will see lots of Youtube video's about how to do it.
Hi, I also have a 2001 C320 and am in need of a fuse diagram. It's nowhere to be found on the vehicle (including "folded up" in the fuse area). If you happen to still have it and could email it to me, I'd very, very much appreciate it! [email protected]