Sorry I can't help, but I want to know also. For 10 bucks you can get the bootleg manual on ebay. One or more members here have it and occasionally post some very helpful docs.Can anyone help on how to remove 3rd brake light?
So what is the little peg?I removed it. Just keep prying on it all around and will come out. There are three metal clips holding it and a double-sided adhesive foam style gasket acting as a seal. That gasket will be destroyed and you'll need to scrape it well and use goo gone to clean completely both sides. I used a clear silicone instead of the gasket to reseal. The clips themselves will still keep the housing in place. Quite possible to break it and destroy the whole unit while attempting to remove.
Mercedes dealer won't do any of that but install a new unit if they need to remove the old for any reason. It's not overly expensive compared to a few hundred $$$ for some other brands. p/n is 447-906-08-00
Hope that helps!