Oil Leak

[Peter Lucas <lucas@xxxx>]

In the course of its long winter's rest, my D has developed a 
non-trivial oil leak. This was completely out of the blue--the engine 
didn't leak at all, then one day there were puddles on the floor.

It appears to be leaking from between the the engine and the (automatic) 
transmission. Do I assume correctly that this is likely the main seal? 
If so, how big a job is it to repair, and what is the easiest procedure?

--Pete Lucas
VIN #06703