Got a leak coming from gear selector

Thats a common shaft seal but it is knocjed in from the top and a real chore to change. Others will share their methods and tools used. I could tell you exactly where to put a hole in the floor pan so you can knock the seal in from inside the car too. Either way if it leaks when finished you get to do it all over again. Best advise I have to offer is take it to a trans shop and let them fix it.