1. Remove the headliner.
2. Remove the nuts.
3. Remove the roof carrier bracket.

4. Install in the reverse order of removal.
Rear spoiler removal/installation
MoldingMazda 6 Service Manual: Dtc c1095, c1096
Caution
When attaching the tester lead to the DSC HU/CM connector the SST
(49 G066 004) must be used.
Diagnostic procedure
...
Mazda 6 Service Manual: Antilock Brake System (ABS)
The ABS control unit continuously monitors the speed of each wheel. If one wheel
is about to lock up, the ABS responds by automatically releasing and reapplying
that wheel's brake.
The driver will feel a slight vibration in the brake pedal and may hear a chattering
noise from the brake system ...