1. Remove the cover.

2. Remove the bolt and child restraint seat anchor.
3. Install in the reverse order of removal.
Buckle switch inspection
SeatMazda 6 Service Manual: Fuel Gauge (Without Multiinformation Display)
The fuel gauge shows approximately how much fuel is remaining in the tank when
the ignition is switched ON. We recommend keeping the tank over 1/4 full.
If the low fuel warning light illuminates or the fuel level is very low, refuel
as soon as possible.
Refer to Warning Lights.
NOTE
...
Mazda 6 Service Manual: Owner Maintenance Precautions
The owner or a qualified service technician should make these vehicle inspections
at the indicated intervals to ensure safe and dependable operation.
Bring any problem to the attention of an Authorized Mazda Dealer or qualified
service technician as soon as possible.
At Least Twice a Year (For ...