Make sure to first have SuperBLT, BeardLib, and WeaponLib installed. Click the links in the dependency list.

Optional video tutorial for installing SuperBLT, BeardLib, and mod_overrides mods: https://youtu.be/rin_sjSJIkg

1. After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
2. Drop that main folder of the mod to assets/mod_overrides. The assets folder is supposed to be in your game's installation folder (don't know where that is? click here). Create the folder if necessary

Extract this into mod_overrides.

You NEED weaponlib for both the correct damage and scope overlay.