Start by prying off one of the boards in the closet. Then, put a pocket mirror into the gap between the floor and the wall to get a sense of how thick the veneer is. If you can see nails, do not worry because it doesn’t necessarily mean that the floor cannot be sanded. If the nails have been driven through the faces of the planks and are sticking out from the top, they can be driven further down using a nail punch before we sand. The holes will be filled before sanding as well.