Leaking 904
Try cleaning trans while still in car, and figure out where it is leaking. Most leaks can be fixed with transmission in car, (borderline PIA), or if it is front pump seal (trans has to come out for that to happen), just hold off until unit is out of the car and replace all the seals at once as it is much easier on the bench than under car to do this.
Dose the transmission currently operate correctly? If so probably the only thing I would do is change filter, inspect & adjust bands, install new base gasket, refill with fresh fluid, and call it good.