1. For those who don't have any other mods, simply drop data3.pak in "Steam\steamapps\common\Dying Light\DW", and replace when prompted.

2. For those who have other mods, but they don't change data\scripts\inventory\inventory_gaas.scr, open your data3.pak with the tool you prefer (7-zip, winrar, you name it)
Then drop in the free files for manual merge.

3. For those who do have mods that change inventory_gaas.scr, simply open your variant with your preferred text editor (notepad++ recommended), find
Item("Firearm_PistolASilenced", CategoryType_Firearm), then find skintag within this one, and change it from Weapon_Craft1 to Weapon_Craft0
repeat for Item("Firearm_PistolBSilenced", CategoryType_Firearm)