There's a PDF manual available somewhere, but this might be the part you need:

BUZZER OPERATION MODE

The factory setting for the buzzer mode is buzzer ON. Selecting the buzzer OFF mode only affects the buzzer operation during remote arming and disarming.

To change the buzzer operation mode, follow the steps below:

1) Sit in the driver seat with all doors and the tailgate window closed. (Tailgate window??)

2) Press and release the remote control's top button once to lock the doors, then once again to unlock the driver door only.

3) Open the driver door only.

4) Insert the key into the ignition switch and turn it to "ON" (not "ACC") 5 times (LOCK=>ON=>OFF=>ON=>OFF=>ON=>OFF=>ON=>OFF=>ON) within a 10 second period.

o The buzzer chirps once.
o The vehicle's marker lights and parking lights will flash once.
o The status indicator LED will turn on for 30 seconds.

--YOU MUST PERFORM THE NEXT STEPS WITHIN 30 SECONDS--

5) Select the operation mode

BUZZER OFF
A) Close the driver door
B) Turn the ignition switch off
o The buzzer chirps once
o The marker lights and parking lights flash once

BUZZER ON
A) Close the driver door, then open and close it again.
B) Turn the ignition switch off
o The buzzer chirps twice
o The marker lights and parking lights flash twice