the plastic housing on top of the engine? The front part by the radiator seems to pop out, But the sides and rear did not. I did not want to force anything with the possibility of breaking it. Does it just snap on? Thanks for the help. I have a 2002 CLK430

 

Yes, it just snaps on and off. But pull it off carefully and as straight up as possible, not at an angle. It takes some force but do it carefully so you won't break anything.