http://www.peachparts.com/shopforum/showthread.php?threadid=37634&perpage=15&highlight=E320&pagenumber=1
http://www.peachparts.com/shopforum/showthread.php?threadid=37925&perpage=15&highlight=E320&pagenumber=2
Here are a couple threads when I did the cyl head gasket on my E320. It is a diyer job - just take your time. Also, you will need the "shortened" version of the head bolt socket to get to the rear most head bolts. I am not sure the size but I was thinking it was not quite a "torx" fastener. You can purchase the correct socket from the Snap On dealer.