yes, get someone else to do it

Not a bad job, but a bit messy.
Basically...
Get replacement gaskets / Filter (JPAT are a good source, or Dave Kember in the back of the Autobahn mag if you have one)
although you can use liquid gasket, and wash the filter in parafin as it doesnt get blocked)
Drop both sumps off the gearbox, i would leave a couple of bolts loosely in so you can 'slosh' the old atf out.
drop and clean both sumps, remove magnet and clean, remove old gasket.
replace or clean filter
refit sumps
fill with nice new dex3 (may I suggest Fuchs titan 4000 from opie oils)
through the level plug, you can use a large syringe for this, or a garden pressure sprayer also works well.
fill till fulid dribbles out, get the car level, start it and work through the gears, top up again, level car, fit plug back in.
Go for a few miles drive, and recheck the level (again jack it up, fill to overflowing, lower to flat, all with engine running, raise to refit plug.
You are now done and have changed about 2/3 of the atf.
Some people do this again after a few weeks to further dilute the atf you cant change.