My transmission is off the car right now for a rebuild. I got the trans overhaul kit, friction discs for K1, K2 and B3 reverse.

While the trans is off the car, I am debating whether to go for the engine rear main seal as well. In my research, I have gotten mixed information as to how to replace the rear main seal - a 91 560SEL. Some threads I have read says I need to remove the engine oil pan, others say no need to remove the engine oil pan? for those that have done this before, can you chime-in on how it is really done? Would appreciate any inputs. thx