You don't. These are found in the game world by looting. Good places to look are military areas or gunstores.

kinda new to all this where do i find the mod and how do I equip it like I know how to enable it but where to I find it to put it on my character before starting the game?

thank you for the mod, i was bummed when I notice there is only around 3 colour now I can look fab in zombo apocalypse

nice job