Remove cover to drain, rtv will work fine to re seal the cover as long as both mating surfaces are clean & oil free. To fill it back up you will find a pipe plug
usually on the passenger side of the front snout, fill it with gear oil till it trickles out of the same hole put the plug back in and your done except for the shower you'll need to remove the smell of gear oil from your body.
I hate the smell of gear oil.