Automatic transmission fluid change.

D16A7 hooked up to M48A slush pump.
Apparently you can replace your ATF at home by draining what will come out and filling the amount that comes out 3 times. So i want to do this.
But i was wondering, how much should come out if i just open the drain hole and let it go? I need to know so i don't buy 5 times too much or one fifth of what i need lol.
Apparently you can replace your ATF at home by draining what will come out and filling the amount that comes out 3 times. So i want to do this.
But i was wondering, how much should come out if i just open the drain hole and let it go? I need to know so i don't buy 5 times too much or one fifth of what i need lol.