I thought about rebuilding mine. But the problem is, how are you going to get the tranny out and in of the car? Do you have a lift at your house and do you have all the nessesary tools?
If you can get a place to take it out and take it home to the garage and tinker with it you can. To get the "rebuilt kits" is around $500.00 or so.
I didnt rebuilt mine myself so i cant help you with the tech details. If I had the time and resources I would have done it myself.