How do you replace your belt on a Mercedes 300 e?

Depending on model first remove two(2) piece fan shroud,the tensioner is located between the water pump and power steer pump,between the pump pulleys is a 10mll. socket head bolt,loosen this bolt several turns,the pre-tension bolt is located behind the power steer pump and is a 13mll.socket size,turn the bolt anti-clockwise to release the tension,if you dont have a belt diagram make one now,pull the belt to loosen it and remove from the pulleys,fit the belt per the diagram leaving the alternator pulley to last,pull the belt whilst loosening the pre tensioner until you can fit the belt over the alternator pulley,pre-tension the belt by turning the pre-tensioner bolt clockwise,do not overtighten,retighten 10mll tensioner bolt,start engine,check belt is correctly aligned on pulleys,retension if neccesary,refit shrouds.