Installation of Bool It addon :

1/ Download the .zip addon file 

2/ Then open Blender and from the menu, go to "Edit -> Preferences -> "Add-ons" -> "Install"

3/ Copy modifier addon will appear on the list of addons, search it and activate it.

Location of the the interface: 3d viewport > Object mode > Bool It

4/ Look at the video on the product page. Bool it is pretty simple but cool.