I need to remove the gavel picture on this page but I still want it to be the featured images
Just delete the picture from within the post. From the post editor, on the right hand side, there should be an area that says something along the lines of set featured image (unless it's already set in which case it'll show the image). Just click that link and find your picture. When you find it rather than hit the button that says insert into post hit the one that says use as featured image instead. Update the post and you should be good to go.