rear main seal leak

That's because there isn't a very simple answer. That's generally a pretty major job. You will need a repair manual: http://bit.ly/mitchell_repair_manuals_online But you may benefit from seeking assistance from a professional.

A rear main seal can be a lot of work because its where the engine meets the trans. You need a detailed guide to do this that is why nobody can give you an easy answer.

on my 2000 E 4matic I have had estimated from $2,200 MB dealer to $655 in Broklyn NY. Have not gone anything yet