Add file to C:\Program Files (x86)\Steam\steamapps\common\the witcher 2\CookedPC\items (steam version)
for credits https://www.nexusmods.com/witcher2/mods/365 and https://forums.nexusmods.com/index.php?/topic/964726-all-items-and-hidden-items-at-mysterious-merchant/
This is my first mod so please don't come for help to I can't understand modding at all ;(