Warning! The vehicle's seat belts must be replaced if they are torn, frayed, or have been subjected to critical stress in an accident.
To replace the front seat belt on your car, you will need: a Phillips-head screwdriver, 8 mm and 17 mm wrenches.
1. Remove the center pillar trims (see "Removal and installation the center pillar trims").
2. Remove the two screws securing the seat belt guide loop...
3. ...and remove the loop.
4. Remove the bolt securing the seat belt inertia reel to the center pillar bracket...
5. ...and remove the seat belt inertia reel.
6. Loosen the seat belt inertia reel mounting bracket bolt and remove the bracket.
7. Remove the two bolts securing the upper mounting point adjustment mechanism...
8. ...and remove the mechanism.
9. Remove the front seat (see "Removal and installation the front seat").
10. Remove the two screws securing the front seat inner trim...
11. ...turn the trim to access the front seat belt buckle mounting bolt...
12. ...unscrew the bolt and remove the seat belt buckle.
13. Install the seat belt buckle on the vehicle in the reverse order of removal.
[Source link - website LADAman]