300SDL transmission swap

[WANT '71 280SEL]

First of all, I'm sorry for double posting but I thought the people who are actual MB techs are probably more likely to have done this before.

I need to do the rear crank seal on my SDL. How long would I be looking at the R&R of the tranny? Obviously that is the main big part of the job. The procedure would be done on a lift with a tranny jack. Also, what other parts would I need? It seems as if the exhaust would be in the way? Will I be able to get all the bellhousing bolts with normal tools? Any tips?

Thanks
David