For b-series, it's about 2.1quarts if I remember. For the d16z6 tranny, its 1.9liters.
If your doing a change of some sort, buy 3 bottles. Undo the 3/8's drain bolt, drain it all out, open the fill hole (about an inch higher then the drain bolt) pour about a third of a bottle with the drain open to flush out the little extra dirty fluid left in there, close the drain, then fill the tranny through the fill hole until it overflows. put the fill plug on to the right trq spec.