Changing 930-transmission fluid...

[beepbeep]

OK, project for the day is changing transsmision-fluid on my 930.

I have:
* 4 liters of 75W90 synthetic GL-5 tranny fluid (should be 3,7 liters in tranny?)
* 17-mm hex tool for undoing the oil-plug (is this right dimension for the plug? it's the bigest hex-plug i could buy)

I'm planning to:
* Lift the car at the shop
* Try to loosen fill-plug first, so i don't need to tow the car in case it's stuck.
* Losen drain-plug with a 17-mm hex bit and stand clear.
* Screw in drain-plug and torque it tightly "by hand" without overdoing it.
* Fill up oil trough fill-hole with small bottle (will bottle fit??)

Questions:
* Is it 17-mm hex bit i need to loosen drain-plug??
* Where is filling hole? On the drivers side?
* Are there any spec-tools involved that i should know about?
* Will this also change oil in diferential or is diff "drainable" as well?

I know i should lift the car and take a look, but there is no lift near my garage...

Thanx as always! )