Select the .materials/.mesh/.png/.jpg files (Basically everything BUT the .cfg file) and place them in FH>Media>Items.
Place the Item.cfg file into the main Feral Heart folder and let it overwrite.
If the download did not come with a Item.cfg and instead stuck the coding in the read_me, copy all the coding, and then open up YOUR item.cfg in the main Feral Heart folder with Notepad and paste the coding into this file, save, and close out.
Your items should work then