1- Choose your favourite one from the "backgrounds" folder and copy/paste it in your "images/warrior/backgrounds" folder (you need to install the skin before doing this).
2- Copy and paste the entire "backgrounds" folder to "images/warrior/" (you need to install the skin before doing this).
Now that this is done, you will need to apply the background in your CSS. To do so, just open your warrior.css file located at images/warrior/. Find:
#bg {
background: url(backgrounds/bg_socom.png) no-repeat fixed center top;
And change the bg_socom with your favourite background.
