found that on another forum:
To teach your alarm system the unique identification code of a replacement alarm remote:
NOTE: Steps 1 through 6 must be performed within 45 seconds.
1) Close all doors, trunk and hood.
2) The alarm must be in 'disarmed' mode and key must be removed from the iginition,
3) Open the trunk and leave it open.
4) Open the driver's door and sit in the seat.
5) Close the driver's door.
6) Cycle the iginition switch 5 times between the OFF position and position #2 (ignition ON position - all dash warning lamps illuminate). The cycling must be done within 10 seconds and do NOT start the car. The red LED will illuminate continuosly and the siren will chirp once indicating the code learning mode has been initiated.
7) Open the driver's door but remain seated.
8) Close the driver's door.
9) Press and release any button on the remote you want to register into the system. The status LED will shut off momentarily to indicate that one ID code has been registered.
10) Repeat steps 7 through 9 to register any additional transmitter codes you wish the system to learn.
11) Open the driver's door and exit the vehicle LEAVING THE DOOR OPEN.
12) Close the trunk.
13) Close the driver's door. The LED will turn off and the siren will chirp twice.
14) Test transmitter to confirm operation.
It is possible for the system to memorize a total of 4 different ID codes. As a new code is learned the oldest code in memory is deleted. To wipe the system of all previous codes simply teach it the code from your current transmitter 4 times.