When I changed mine, I just drained the pan, rotated the Torque converter to line up the drain bolt, and drained it.

replaced the transmission filter, two screws holt it in. cleaned the pan, replaced the gasket, and torqued the pan bolts. It`s only inch Lbs, so don`t go gung ho on them or you will have leaks.

My Haynes manual says
trans filter screws 7nm 5.2 ftlbs
trans pan bolts 7nm 5.2 ftlbs
trans drain plug 14nm 10 ftlbs
torque conv.drain plug 15 nm 11 ftlbs

I washed out the pan, rinsed with brake clean, and air dried it. don`t wipe things down, might leave lint that will get into the trans and cause problems.

Using synthetic shouldn`t hurt anything, the two oils won`t gunk up the trans. If this car is new to you and you don`t have any records of previous services, maybe you will want to do a couple changes before the synthetic.
Look at the present fluid and the bottom of the pan for anything.

I changed ours 12,000 mi ago to syn and it shifts smooth.

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works