Double-click the ATN file then in Photoshop, go to Window > Actions. If you do not see the actions, click on the panel menu (top-right corner of the panel) then click Load Actions. Browse for the "Brick Mosaics by SparkleStock.atn" file then click Load.
OR
Run the *.zxp file and follow the instructions.
Go to your Actions panel (Window > Actions), open the panel menu located on the top-right of your panel, then choose the Brick Mosaics actions.
Using the Photoshop Actions:
In your Actions panel (Window > Actions), click on the "Play All Effects" action.
Go into your History panel (Window > History) and select an effect.