Not sure if it's going to work on your model. I used this for my CX-7. You can try though.
1. Car off, all belts unbuckled, parking brake on
2. Turn key to on position. you will see seat belt warning light light up red
3. After 1 min you must buckle and then unbuckle seat belt you want to disable warning for 9 times exactly and finish doing this within 50 seconds of the light going off
4. Airbag light will go on for 3 seconds or so
5. After it goes off, buckle then unbuckle seat belt again 1 time
6. Light will flash, seat belt warning disabled.