Probably a seal where the CV shafts enter the tranny is where the leak is coming from. (sorry. it's just a guess, but it is the most common place it leaks from)
As far as filling it, there should be two screws (plugs) that are on the side of the tranny. One is right above the other. The bottom one is the drain plug, where you would drain the tranny, hence the name I guess...
The one above that is the fill plug (go figure) You want to fill the tranny with 80W-90 gear oil until it begind to come back out of that top hole. That's how you know it's full.
Word! :hy: