If you have replacement photos, you do not need to delete your old photos. You can upload over the outdated photos by clicking browse in the slot that corresponds to the photo you want to replace in the Upload Featured Photos section. Just select the photo off your computer, open it, and hit save changes. If your photos are in the Additional Photos section, click on that icon and a window will open showing your pictures. Click the Red X under the thumbnail of the picture you want to delete. Then upload your newer pictures in that same area.