You don't need a working remote to program the car to accept a remote.
There is a wiring connector (white IIRC) behind the glove box that must be jumped (I use a paper clip) with the key on. When the car is in the programming mode (I don't remember the signal, but it may be a short horn chirp) push any button on ALL of the remotes you intend to use on the car. Turn off the key and remove the paper clip and then test the remotes. If you don't have all the remotes with you when you program, the ones that you left behind will no longer work until ALL are done again.
That is as best as I remember it. You should be able to find more accurate information with a search.
