Truck Repair: n14 cummins 1998, n14 cummins, oil leakage

Question
have oil leak at the back of the motor can't tell if its the rear main seal just start to leak last week. how to fix myself  and new owner opt. can you just take the oil pan off to fix or have to pull trans and clutch. or look for other leak from the motor it self.

Answer
If the oil leakage is coming out between the flywheel housing and the engine block, it is most probably a rear oil seal problem.
To access this for repair, you need to pull the clutch/gearbox from flywheel housing and remove flywheel assy.

regards,