This part isn’t really necessary, but it always helps to have a backup of some sort for your files. (OPTIONAL) Setting up file format (OPTIONAL) – VTF Shell Extension, lets you see all the preview pics of the vtfs: – Crowbar, highly recommended to use if you wish to retexture something from workshop: – Storage Space, recommended enough just to make a temporary. – An image editing program, PHOTOSHOP IS HIGHLY RECOMMENDED You’ll need a few different things to be able to retexture: I’m assuming you have an editing program of some sort, or at least know how to edit. This is a guide on how to reskin textures for Gmod models, or just source models in general.