You need to pull the pan off the bottom of your gearbox, from memory about 18-20 nuts and it pops straight off.
you need to use a litte care when removing it so as no to damage/bend the dipstick shaft.
you'll also want to change the filter while your doing this, as its pretty much a wase of time chainging fluid otherwise.
and then as you said above, fill it up through the dipstick shaft carefully with a funnel, you spill here & its gona smell reeeeaaal nasty (I know from past experience)
PS I use Penrite oil's fluids, but any goo dextron II fluid will do you fine