A headlight wiper is misaligned on my 86 300e. The owners manual (cd) shows a cover and suggests lifting this cover and unscrewing a nut. My wipers do not have a cover as described by the manual. The wipers are one piece from the point where they attach out past the bend of the arm. There is what appears to be a very small rivet (the size of a head of a pin) towards the base on the wiper arm, located on the bottom on the arm. There must be an easy way to adjust these, any help would be appreciated.