Anyone have any idea how often you should change the fan belt on a 99 ML 430? Mine has 78k on it. The belt looks fine, but wondering if it should be changed anyways. Is it difficult to do (meaning, any harder than any other fan belt change)? I am going to do plugs soon, and figured, since I was in there, if it was time, I would go ahead and do it.

Any tips or tricks on doing it?