From the 2006 owners manual, pg 45:
NOTE: The following steps must occur within the first 60 seconds of the ignition switch being turned to the ON or START position. DaimlerChrysler does not recommend deactivating the Enhanced Warning System (BeltAlert)
1. Turn the ignition key to the OFF position and buckle the drivers seat belt.
2. Start the engine and wait for the seat belt warning light to turn off.
3. Within 60 seconds of starting the vehicle, unbuckle and then rebuckle the
driver's seat belt at least 3 times within 10 seconds, ending with the seat
belt buckled.
4. Turn off the engine. A single chime will sound to signify that you have
successfully completed the programming.
The enhanced Warning System (BeltAlert) can be reactivated by repeating this procedure.
NOTE: Although the Enhanced Warning System (BeltAlert) has been deactivated, the Seat Belt Warning Light will continue to illuminate while the driver's seat belt remains unbuckled.
Hope that helps!!