I have an 1994 ford mustang with an oil leak rear seal i think i want to fix without wemoving the motor?

when the motor gets hot smoke comse out fo the passenger side manifol like its stoped up or somethingI have an 1994 ford mustang with an oil leak rear seal i think i want to fix without wemoving the motor?
If the manifold is smoking it's not your rear main. More likely the valve cover on that side.

cartridge