Here's your tut.. right click and save images.. take the images you've collected from the site your ripping.. add those images to an existing skin you already have installed..in other words.. (right click/save images) from the site your ripping to your desktop.. then after you've go all those images.. find another skin thats similar in templetes,etc..and replace those images with the other site's images you just ripped.. thats a very easy way of doing it.
There are also programs out there that you can use to rip a sites theme or style.. i know there are alot of programs to do flash sites..and html sites so google it
There are other ways..like hacking a site's server and taking the complete skin..it can be done but you need php,webdev,ssl,etc haxx0r skills for that like i have lol but i dont hack such sites..i only hack sites for servers to store warez on their servers..like uni's and company's,etc
Best way for you guys is to do what i suggested..not sure how hoxxy does it but as with alot of things...some people keep their tricks of the trade secret if u know what i mean.