Bass-Box Removal/Installation

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

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