If you have omar's installer, then open the popup go to litestep, changethemes, install theme. When it opens browes for the theme you downloaded and open it. The installer will do the rest via netload. this is the simplest way of doing it, if you would like more info on it just read the docs like we tell everyone else. Which you should do anyway, it will help you greatly, for if nothing else it will give you a greater understanding of how LS works.