I recently had both my keys reset:
Lock the doors using the key not remote.
Do not open for a minute or so.
Open door using the key.
Put key into ignition and turn to Position 1 for a couple of seconds.
Turn ignition off and take key out.
Step outside the vehicle and close the door.
While holding down the unlock button on your remote, press the lock button 3 times.
The doors should lock then unlock.
That key is now programmed.
To set the other key, directly after setting the first key do the same procedure of holding the unlock button on the remote and press the lock button 3 times.
The doors should lock and unlock again.
Job done..