Also, try this method if above one doesn't work
You will need BOTH remote key fobs to reprogram one or both of them.
1. Take the key you DO NOT want to reprogram and put it in the ignition.
2. Turn the ignition on but DO NOT start the engine.
3. Put the second key in the drivers door lock. Whilst it is in the lock press the UNLOCK button once only (the lights should flash on the car but the doors will remain locked).
4. With the second key still in the drivers do