Installing Actions in Photoshop 

Adobe Photoshop action files have an extension of .atn. Installing actions in Photoshop is referred to as Loading actions. To load a set of actions into Photoshop, do one of the following: 

1. From the Actions Panel menu, choose Load Actions… Locate the action set, and then click Load. 

2. In most cases, you can find the action set in Finder (Mac) or Windows Explorer (Windows). Double click on the action and Photoshop should open up and automatically install the action.