Hi, my daughters car is a 96 Cavalier LS with 2.2L, 4 speed auto.... Tranny fluid is leaking from where the passenger side axle exits the tranny, not a huge leak but enough so that I had to add fluid (about a pint)... How difficult is it to change that seal, has anyone ever done this?

I did it on my son's 97 Z24. Probably the same transmission. Buy a Chilton manual and it lays it out reasonably clearly. It involves removing the hub and then undoing a snap ring in the transmission by prying the axle out. I found pulling the old seal out was the hardest as room is at a premium. I got it all back together and it didn't leak. An afternoon job if you are handy.

Thanks, are you referring to a special Chilton's manual for transmissions, or just the normal one for general repairs? I have a Haynes manual that should tell me how to get the axle out, then if there is just a snap ring holding in the seal, that does not sound too bad....

I had the manual for the entire car. Used it to rebuild the engine as well. Probably not as complete as GM shop manual but pretty good.
The snap ring is holding the axle into the transmission you have to use a pry bar to pry it out. The seal itself is an interference fit to the trans housing.
When putting the seal back I think it might be a good idea to put a bit of gasket sealer on the outside just so oil doesn't run between the trans housing and the seal housing.