Do you want to create a new eye set or replace a current one? The latter is far easier, I would imagine, since it just involves retexturing a set. The former, as you said, likely revolves around the CK in the sense that you need to create the textures and then hook it up with the CK so it recognizes the eyes as a new set. I was planning on replacing a current one if it was easier. If I could find a tutorial I would try to make a standalone but, I mostly want to know how for either.