There is no easy way to do this. Basically, car on the level. remove the filler plug and drain off what you can. Then syphone more out using a syphone, a tube etc.
Try and get at least 3 litres out. Next, drop the main sump, but be aware that it will be over 1/2 full of this crap. It stinks and will make you feel sick if you berath it for too long, Laidback and I found out the hard way!
The bellhousing has no oil in, just air. The torque convertor will have up to 2 litres in and you will not be able to get this out.
You will need about 5 litres of new ATF Dexron III and a garden npressure bottle, the type with a handle you pump up is best. refil the box (after changing the filter and cleaning the sumps) until it flows back out the sump plug. Then start the engine. Continue filling untilk the atf flows out again, then plug the sump and job is done.