How on earth do they work and how do I put them on in nifskope when I re-texture a model? They can't be inherent in the texture file, because when I load up textures, no shading appears. So it has to be something applied in nifskope, right? I just can't find out how to do it, even after searching google.

Anybody have any advice or direction? Much appreciated.

Well; I can't tell you how to do it in Nifskope, but if you have blender I can definitely help you there.