I assume there is a little seal around the shift shaft on a 700R4. I assume this because it is leaking. Can this be changed with the trans in the car, and if so can a dummy like me do it?

I havent done it my self but it seems to be "easy"
according to the following link.

http://www.hotrodders.com/forum/th350-leaking-through-shifter-linkage-hole-90521.html