Download the mod.
Navigate to your NieRAutomata game directory (\SteamLibrary\steamapps\common\NieRAutomata\).
Unzip to this directory (merge the \data\ folders).
Enjoy your day.

To uninstall, simply remove the pl000d.dat and pl000d.dtt files in \SteamLibrary\steamapps\common\NieRAutomata\data\pl\.