Since I have not found a decent manual for my 1986 300e, could anyone tell me what the procedure and difficulties are in removing and re-installing a master cylinder and brake booster?

 

If you don't mind posting your e-mail add. here, I would send you a copy of the PDF file= full procedure.

 

Unhook all brake lines from your Mercedes master cyclinder. Unhook plunger from brake pedal assembly. Unhook booster hose. Remove bolts holding it to the firewall and pull it out. Get ready for a huge mess of spilling brake fluid, unless you drain it first... That truth is that it is really difficult to change it.. Goodluck...