I can't change my skin, but it's a little more complicated than that. I know how, but I have an old premium account that isn't linked to a mojang one. So if any of you know your way around the java side of things, or even know how to work with the minecraft website and account migrations let me know. Although before you comment anything watch this first. It explains it a lot better and with some fun graphics. Any help would be appreciated.

I can't change my skin. (The video)