Here are the *less destructive* options, but understand they all involve some level of automotive electrical knowledge and risk:
* Locate and disconnect the beeper itself: This is the cleanest approach, but the hardest. You'll need to trace the wiring harness from the seatbelt buckle switches and door switches to find the beeper unit (it's likely a small, separate component somewhere under the dash). This requires patience, careful observation, and potentially a wiring diagram (a Haynes or Chilton manual might help). Once located, you can carefully disconnect its power supply. Warning: This could be more complex than it sounds, and you risk damaging other components if not done carefully.
* Bypass the switches: This is less ideal, but potentially easier. You can try identifying the wires going to the seatbelt buckle switches and the door ajar switches. Then, you'd carefully connect those wires together, essentially fooling the system into thinking the seatbelts are buckled and the doors are closed. Again, this requires a wiring diagram and a good understanding of automotive electrical systems. Connecting the wrong wires can damage the car's electrical system.
* Install a switch: A more sophisticated approach involves installing a switch in the circuit. This allows you to turn the beeper on or off as needed. This still requires you to locate the correct wires and understand basic wiring principles.
Why these are risky and not recommended for the average person:
* Wiring diagrams are essential: You absolutely need the correct wiring diagram for your specific 1987 Honda Accord model. Guessing could lead to short circuits or damage to the car's electrical system.
* Electrical knowledge is required: Working with car electronics requires a decent understanding of automotive electrical systems. Improper connections can cause short circuits, blown fuses, or even fires.
* Safety implications: The beeper is a safety feature designed to remind you to buckle up and ensure all doors are properly closed. Disconnecting it removes this crucial safety reminder.
Recommendation: If you lack experience with automotive electrical systems, it's best to leave this task to a qualified mechanic. The cost of having a mechanic do it will likely be far less than the cost of fixing damage caused by an incorrect attempt to do it yourself. The annoyance of the beeper is minor compared to the potential problems from DIY electrical work.