Yes , You can But what exactly you mean? Are you talking about using the CK to change the item nif paths? If you change that path in the CK, the game will look for the model in the new folder, if you choose a pre-existing folder like the Elven boots for Daedric Boots, what it will happen is that everytime somebody wear the Daedric boots, the model you will see ingame is the one from elven boots. If you decide to create a new folder, just make sure once you close the CK that you create that folder exactly in that place inside the "Meshes" folder with the nif folders, or your character will wear an invisible armor because the game found no nif and no folder to load (thus no model, thus remain invisible)