Be extremely careful! The door trim on the CL500 is difficult and sensitive. My best friend has 1998 CL500 which I took for her to the dealer to have the lightbulb for the electric seat switch change. In the process of reassembling the door, the dealer broke the window (double-pane) and the whole deal became a very expensive mistake (for them!).
My best advice: take to it to an authorized M.B. dealer and have them fix it.