Hi Dave.....welcome to the Forum
Try this, hopefully it will work
Nissan Key Fob Programming Instructions
Sit in the driver's seat of your Nissan. Close and lock the doors.
Insert your key in the ignition. Turn the key to "ACC," turn it off and remove it from the ignition. Repeat this process six times in rapid succession. ...
Insert the key into the ignition. Turn the key to "ACC." Push and release any button on the remote.