1. Disconnect the negative battery cable.
2. Remove the dashboard. (See DASHBOARD REMOVAL/INSTALLATION.)
3. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
4. Remove the blower unit.

5. Install in the reverse order of removal.
Basic system
Blower unit disassembly/assemblyMazda 6 Service Manual: Lane Departure Warning
If the system determines that the vehicle may deviate from its lane, the lane
departure warning (beep sound, rumble sound*1, or steering wheel vibration) is activated
and the direction in which the system determines that the vehicle may deviate is
indicated in the multi-information display and ...
Mazda 6 Service Manual: Rear oil seal
REAR OIL SEAL REPLACEMENT
1. Remove the flywheel. (MTX) (See CLUTCH UNIT REMOVAL/INSTALLATION)
2. Remove the drive plate. (ATX) (See DRIVE PLATE REMOVAL/INSTALLATION)
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Rear Oil Seal Installation Note
...