You need BepInEx
Mod Install:
Green Hell\BepInEx\plugins\QuieterWatch .dll
Mod Config:
(start the game 1x)
Green Hell\BepInEx\config\shaklin.QuieterWatch .cfg

You need UnityModManager
Mod Install:
Drag&Drop into UnityModManager or click under 'Mods' on 'Install Mod'
Mod Config:
(start the game 1x)
Green Hell\Mods\QuieterWatch\QuieterWatch.ini