Re & Re center piece

With much slach and noise in the differential the time has come to change this unit. I have a few questions before I start the job.

Can the center piece be removed without drawing the axels out of the wheels if the wheels are hanging down to their full extention on the shocks.

Will the drive shaft have be shortened up at the spline,or can I pull the center piece away and to the read after undoing the three flange bolts without touching the drive shaft.

The service manual for the 300D did not show a gasket fot the rear door. Is this a steel to steel fit with Form-a-Gasket.

I have learned so much from reading this board.
Thank a lot.

John Winter
300D turbo 84, the wifes car
240D 74, my car