1. Remove the front door unit.
2. Remove the screws, then remove the front door latch and door lock actuator.

3. Install in the reverse order of removal.
Rear door unit removal/installation
Rear door latch and lock actuator removal/installationMazda 6 Service Manual: Dtc b1318
Caution
When attaching the tester lead to the ABS (ABS/TCS) HU/CM harness
connector, the SST (49 G066 001) must be used. (See ABS (ABS/TCS) HU/CM
INSPECTION.)
Diagnostic procedure
...
Mazda 6 Service Manual: Using LATCH Lower Anchor
Your Mazda is equipped with LATCH lower anchors for attachment of specially designed
LATCH child-restraint systems in the rear seats. Both anchors must be used, otherwise
the seat will bounce around and put the child in danger. Most LATCH child-restraint
systems must also be used in conjunctio ...