Do you want to remove the whole restraint belt and retractor? or just unbolt it from the seat itself?
If you're just taking out the seat, it's a Torx bit near the bottom
If you're taking out the whole restraint belt, the Factory Service CD says:
1. Remove the B-Pillar trim panel.
2. Remove the scuff plate trim panel.
3. Detach the safety belt from the B-Pillar
- Detach the safety belt upper anchor.
- Detach the waist loop guide.
4. Remove the safety belt retractor
1 Remove the screw.
2 Remove the Torx bolt.