If the selector lever will not move from P using the proper shift procedure, continue to hold down the brake pedal.
1. Remove the shift-lock override cover using a cloth-wrapped flat head screwdriver.
2. Insert a screwdriver and push it down.

3. Press and hold the lock-release button.
4. Move the selector lever.
Take the vehicle to an Authorized Mazda Dealer to have the system checked.
Shift-Lock System
Transaxle RangesMazda 6 Owners 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.
...
Mazda 6 Owners Manual: Oil cooler removal/installation
1. Disconnect the negative battery cable.
2. Drain the ATF into a container. (See AUTOMATIC TRANSAXLE FLUID (ATF)
REPLACEMENT.)
3. Remove the radiator. (See RADIATOR REMOVAL/INSTALLATION.)
4. Remove in the order indicated in the table.
5. Install in the reverse order of removal.
6. Add ATF to ...