Replacing key fob outer case, help!!!
If it's oval you can swap it. You just take out the blade key remove the battery tray use a big paperclips to lasso the white plastic tray piece and yank out the circuit board. Put it into the new key case you need to transfer the metal key and circuit board you don't need the battery tray from the old one.
If not you will have to get the key reprogrammed. And dealership won't do it unless you got it from them. GL
My experience with keys was when I ordered a new one to complete my set as my previous sedan only came with one key. That was 2 years ago and to be honest i didn't try to go cheap on this since having the right key was important to me. But I guess if I have to do it again I'll try to avoid the MB tax



