With Center Display

WARNING: This page is about a different car, the 2017 Mazda 3. 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 following parts:
1. Front scuff plate (RH) (See FRONT SCUFF PLATE REMOVAL/INSTALLATION .)
2. Front side trim (RH) (See FRONT SIDE TRIM REMOVAL/INSTALLATION .)
3. Glove compartment (See GLOVE COMPARTMENT REMOVAL/INSTALLATION .)
4. A-pillar trim (RH) (See A-PILLAR TRIM REMOVAL/INSTALLATION .)
Remove the clips A, B, C and D.

Fig 1: Locating Antenna Feeder No. 1 Clips A, B, C And D
Courtesy of MAZDA MOTORS CORP.
Remove the antenna feeder No. 1.
Install in the reverse order of removal.