The floor will sit in the lower position without modifying anything. There is a thread here somewhere, but basically you put in the front UNDER the plastic retainer pieces then pull it toward you. It WILL be right on top of the spare tire, but it works. I use the space created by having it in the stock position to "hide" things like an air compressor, jump start battery, cleaning products, etc that I don't want in the "trunk" sliding around.