Horn Removal/Installation

WARNING: This page is about a different car, the 2016 Mazda CX-5. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION .)
Remove the front bumper. (See FRONT BUMPER REMOVAL/INSTALLATION .)
Disconnect the connector.

Fig 1: Identifying Horn Bolt With Torque Specifications
Courtesy of MAZDA MOTORS CORP.
Remove the bolt.
Remove the horn.
Install in the reverse order of removal.