Catch Everest: homepage settings

Hi there, I have installed the Catch Everest theme and am keen to use the idea of the four slider images but with my own pictures. I can't seem to do this and have disabled the four slider images for the time being. Can I alter these images for my own ones? Or even just use one of my own as a static image? And how do I insert categories (tabs that link to the tabs below my site title and tagline?) on the far right so that it looks more like a blog? Thanks, Abi