Take the appropriate action and verify that the warning light turns off.

Taking Action
Message Indicated on DisplayMazda 6 Owners Manual: Automatic Transaxle Controls
Various Lockouts:
Indicates that you must depress the brake
pedal and hold in the lock-release button to shift (The ignition must be switched
ON).
Indicates the shift lever can be shifted
freely into any position.
Indicates that you must hold in the lock-release
button to shift.
N ...
Mazda 6 Owners Manual: Parking brake (lever type) removal/installation
1. Remove the center console. (See CONSOLE REMOVAL/INSTALLATION.)
2. Remove the rear seat cushion (4SD) or rear seat (5HB) . (See REAR SEAT
REMOVAL/
INSTALLATION.)
3. Remove the exhaust pipe bracket.
4. Remove in the order indicated in the table.
5. Install in the reverse order of removal.
6 ...