For Photohop 7, Photochop CS and Photoshop Creative Cloud:
Thanks to Atomic Cupcake for allowing us to reprint these!
1. Copy the .atn files to the location of your choice
2. Open Photoshop. Open the actions panel (WINDOW>ACTIONS).
3. Click on the contextual menu (icon with 4 thin lines) in the top corner of
the Actions panel and click “LOAD ACTIONS.” Navigate to the ATN file on your computer and select it. Click OPEN.