While you might find some online forums suggesting workarounds (like using aftermarket devices or manipulating the wiring), these are often unreliable, may damage your car's electrical system, and are generally not worth the risk.
Instead of disabling the chime, consider these alternatives:
* Buckle up: The simplest and safest solution. The chime is there for a reason.
* Address the root cause: If the chime is annoying you because you're frequently forgetting to buckle up, try to create a habit of buckling up immediately upon getting into the car.
* Temporary solutions (use with caution): Some people wedge something small and soft into the buckle to trick the system. This is a temporary and unreliable fix, and could potentially damage the buckle mechanism over time. Do not attempt this.
In short, while it might seem like a minor inconvenience, the seatbelt chime is a vital safety feature. It's best to leave it enabled.