1. Insert the key into the ignition and turn it to the "ON" position without starting the engine.
2. Within 5 seconds, turn the key back to the "OFF" position.
3. Repeat step 2 three times.
4. On the third time of turning the key back to the "OFF" position, leave it in the "OFF" position for 10 seconds.
5. Turn the key to the "ON" position and start the engine.
The car alarm should now be reset. If the alarm does not reset, you may need to consult your owner's manual or a professional mechanic.