How do you re-program a 2009 sonata key fob?

To reprogram a 2009 Hyundai Sonata key fob, first, sit in the car and close all doors. Insert the key into the ignition and turn it to the "On" position without starting the engine. Press and hold the "Lock" button on the key fob for about 5-10 seconds, then turn the ignition off. Finally, test the key fob to ensure it’s working properly. If this method doesn't work, consult your owner's manual or a professional locksmith for assistance.