I can tell you what the principle is, I don't have much time today to get into details.
What you need to build is:
one element (section) containing a pile of divs placed in absolute, each having a different background and each set to opacity 0 (minus the first one, set to opacity 100%). give a unique class to each element (bg-tab-1 etc for example)
another element containing your tabs element
Also you need an interaction for each of your tabs. This interaction will say : onclick, affect another element (target bg-tab-#, the one you want to show up) then set it to opacity 100%. Also add other steps, still affecting other elements, for each of the elements you don't want to show up, setting them to opacity 0)
So the logic is : each time you click on a tab, it says to one div containing one bg to show up at opacity 100% and says to all the other elements to disappear to opacity 0. So you'll end up with one interaction by tab.