Caution
4SD
1. Fold the rear seat back.
2. Remove the rear package trim.
3. Remove the bolt.

4. Remove the rear center seat belt.
5. Install in the reverse order of removal.
5HB
1. Remove the rear scuff plate.
2. Remove the tire house trim.
3. Remove the trunk side upper trim.
4. Remove the C-pillar trims.
5. Remove the bolts.

6. Remove the rear center seat belt.
7. Install in the reverse order of removal.
Rear side seat belt removal/installation
Front buckle removal/installationMazda 6 Service Manual: Rear seat disassembly/assembly
4SD
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
5HB
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
...
Mazda 6 Service Manual: Drive belt auto tensioner inspection
1. Remove the drive belt. (See DRIVE BELT REPLACEMENT.)
2. Verify that the drive belt auto tensioner moves smoothly in the
operational direction.
Replace the drive belt auto tensioner if necessary.
3. Turn the drive belt auto tensioner pulley by hand and verify that it
rotates smoothly ...