W163 - 2001 ML320; W208 - 2002 CLK320
Save yourself some future problems and $$. Get yourself a cup of coffee and do this maintenance. An easy five minutes !
It unclips from the opposite side of the wiper arm and slide off on the wiper arm shaft ONCE it is removed. Don't pull on it to remove. After instruction #4 in removal step, there should be a #5 step where you remove the large plastic cover.Does the large plastic cover just un-clip/pull off from underneath?