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

3. Install in the reverse order of removal.
Front door latch and lock actuator removal/installation
Front door key cylinder removal/installationMazda 6 Service Manual: C-pillar trim removal/installation
4SD
1. Remove the tire house trim.
2. Turn the seaming welt over.
3. Remove the cap using a fastener remover, and remove the bolt (with curtain
air bag system).
4. Disengage clips A and clip B using a fastener remover.
5. Pull the C-pillar trim forward, then disengage hook C from the body, ...
Mazda 6 Service Manual: Electrical parts
Battery cable
Before disconnecting connectors or removing electrical parts, disconnect
the negative battery cable.
Wiring Harness
To remove the wiring harness from the clip in the
engine room, pry up the hook of the clip using a
flathead screwdriver.
...