How to install custom shapes (.chs files) :
-Put the (.chs) file you’ve downloaded into the folder
(on Windows)C:\Program Files\Adobe\Photoshop\Presets\Custom Shapes
(on Mac) /Users/{YOUR USERNAME}/Library/Application Support/Adobe/Adobe Photoshop ___/
-Then open your Adobe Photoshop, active shapes tool, go to option palette and click on to open the custom shapes preset
or Drag and Drop on Photoshop