as jacko showed you by his link
1) Plug seatbelt in.
2) Turn key to the on position, engine off. Wait for seatbelt light to go off,
3) Undo and redo the seatbelt 3 times, leaving it buckled the last time. (When you undo and re-do the seatbelt the three times, you actually have to put the seat belt all the way back to the post its mounted to)
4) Turn the key off and you should hear a chime indicating that you disabled the chime.
this 100% works, i did this 2 years ago and never had to do it again.
Edit: here's a random youtube video showing the same process
11 Mineral Gray Metallic Compass 2.4L, 4x4, Auto Mods/Addons:
Pioneer AVIC-X910BT Radio + Jensen JCAM1 Rearview Backup Cam, K&N 63-1567 Performance Intake , Magnaflow Exhaust Part #16777 (Yes it will fit on a 4x4 2011 Compass), Mopar Chrome Fuel Door, Cargo Area Security Cover, Husky floor mats, Mopar Front & Rear Molded Splash Guards