Thanks ssgharkness020147 - that worked to program the transmitters! I'm going to assume the button on the 2001 does the same thing the grounding of that wire does on the 1996, but I haven't had a chance to try that yet.
I also couldn't get the horn chirp feature to be reactivated though I followed the procedure on your link several times.
Thanks again for the help, and if anyone has any idea how to reactivate the horn chirp or what I might be doing wrong, please let me know.