How to remove a photo from your site
To replace a photo, simply tap on the image, and either look for a new image in Unsplash or tap ‘Choose an image’ to upload one from your device, then publish your site again.
If you don't want to have a picture in a block which currently has one, you can make the block a Text block using the recycle icon in the top right corner of that block.
If the images that you want to remove are in a Gallery block, you can delete the entire block in Erase mode.