Access existing sliders via Slider Revolution (located toward the bottom of the left admin navigation)
Access / click duplicate from an existing slider
Replace image on the newly duplicated slider (upload image measuring 2536px × 754px to media library for this purpose)
Your new slider will automatically appear in the drop-down menu offered as part of the Fusion Page Options located at the bottom of the page edit screen … details about changing the slider a page displays are here.