Bass-Box Removal/Installation

WARNING: This page is about a different car, the 2017 Mazda CX-9. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Remove the trunk covering. (See TRUNK COVERING REMOVAL/INSTALLATION .)
Remove the trunk board. (See TRUNK BOARD REMOVAL/INSTALLATION .)
Remove the bolt.

Fig 1: Bass-Box, Connector And Bolt With Torque Specification
Courtesy of MAZDA MOTORS CORP.
Disconnect the connector.
Remove the bass-box.
Install in the reverse order of removal.