How to remove your background video & images

Hello,

So you don't allow us to attach an image so I will explain this the best I can.

How do I remove original template videos & images for example the videos on video slider? I've been able to replace and add my own on the first one. But the last one, it will not move even after I changed with my info.

I want to remove this: element.style {
background-image: url( i.vimeocdn.com/video/480990585.webp?mw=500&mh=281 );

Thanks
a

I sent a print screen to you.. but its joomlaux images and videos downloaded with the quickstart demo. For example I inserted my video, deleted the demo url and the demo video still shows..