How do I change them?

Can we use the w209 mounts I heard they were better?
Can an Indy shop do it? If so how much?

I now have a knocking noise from my car and I need to chang them as we'll as my transmission mount

i remember reading in the benzworld.org board that the 209 mount is interchangable and better. there is also a DIY over there as well. did you use the search function here?