5 Door

WARNING: This page is about a different car, the 2004 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Remove the nuts.
Detach clips A and remove the radiator grille.
Install in the reverse order of removal.

Fig 1: Radiator Grille - 5 Door With Torque Specifications
Courtesy of MAZDA MOTORS CORP.