To the OP, I would highly recommend that you DO NOT follow this procedure, basically as advised in that last sentence. If you want to disable your seat-belt warning chime, take it into Toyota and ask them to turn this feature off. It can be done via the ECU, just bear in mind that if you ever disconnect your battery, it will restore back to default which is on. In cars equipped with airbags, the seat-belt buckle switch is tied in with the SRS system. Tampering with this is essentially the same as tampering with the SRS system which can either reduce it's effectiveness and/or invalidate warranty/insurance in a worst-case scenario.