Interior, Front

Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [LF] .)
Remove the scuff plate. (See SCUFF PLATE REMOVAL/INSTALLATION .)
Remove the side panel. (See SIDE PANEL REMOVAL/INSTALLATION .)
Partially peel back the floor covering so that the foot support can be removed.
Remove the foot support.
Disconnect the connector, then remove the screws.
Remove the keyless antenna.

Fig 1: Removing Keyless Antenna - Interior Front
Courtesy of MAZDA MOTORS CORP.
Install in the reverse order of removal.