I'm not gonna get dragged into a debate as to whether seatbelts should always be worn or not, but this is what previous Jeep models had in their owners manuals - not sure if the Renegade has something similar:
1. Turn the ignition switch to the OFF position, and buckle the driver's seat belt.
2. Turn the ignition key to the ACCESSORY/RUN position (engine does not need to be running), and wait for the Seat Belt Warning Light to turn off.
3. Within 60 seconds of starting the vehicle, unbuckle and then re-buckle the driver's seat belt at least three times within 10 seconds, ending with the seat belt buckled.
4. Turn the ignition key to the OFF position. 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.
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 unfastened."