Hello,

You need to go to the Slider Revolution and change images and backgrounds.

First of all, enter the editing mode of the page where the Slider Revolution displayed. Check which one is used as shown here: http://prntscr.com/isshej

Then find this slider in Slider Revolution plugin as shown: http://prntscr.com/issi0h

You will find more manuals how to edit slider as per your needs here: https://www.themepunch.com/revsliderjquery-doc/slider-revolution-jquery-5-x-documentation/

Best Regards