I just looked at the instructions its hard to explain without the illustrations. There is a company that independent auto repair shops buy their information from that the same information inexpensively to do it yourselfers. The information is year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online
You can buy the class only from Mercedes or a whole mirror from www.rockauto.com or clearview but the mirrors come in black and have to be painted body color.