Mod was done for making good-lookin' inventory icons for custom items (weapons, melees, throwables, masks).
Move every file from archive into Payday 2 directory.
_For_Inventory_icon.bat was done for fast activation and deactivation of mod. It's safe to use it.
Bat will automatically spot mod (or lack of mod), rename all folders in mod_overrides, add.xml and mod.txt to deactivate mod and vice versa.