How do you program keyless remote 2004 impala?

To program a keyless remote for a 2004 Chevy Impala, first, sit in the driver's seat and close all doors. Insert the key into the ignition and turn it to the "On" position without starting the engine, then press the brake pedal and press the "Unlock" button on the driver's door. Turn the ignition to "Off" and repeat this process two more times. Finally, turn the ignition back to "On," and within 10 seconds, press and hold the "Lock" and "Unlock" buttons on the remote for about 15 seconds until you hear a chime, indicating successful programming.