How do I install the script?

This script is not a Blender addon, hence you do not install it like an addon. Keeping the code as just a script allows for per project customization. Just load the script and run it once when you need it.

To run the script open Blender’s “Scripting” layout. Click on the open button and navigate to the script and select it. Afterwards scroll to the end of the bar and click on “Run Script”.