Slider

I am using the SHK theme and already setup the home page to use the “homepage” template. I´ve followed the other topic that asks this same question also, but I canoot understand where I can go to change the images and text to the Demo Slider or create a new category that will show when we select the Category Slider. Can you clarify the steps to achieve that, please? Thanks in advance.

The page I need help with: [log in to see the link]