[31Tudor]

Most running board trims are designed to do as you describe, hook over the top and then snap over the bottom. You will not bend anything as they are pre-made to fit. You can slide them on end to end, carefully. On real 31 running boards, the little rubber lip on the end trim molding actually lays over the trim molding on the very outside edge. If you slide them on end to end, you would want to be careful not to shear that little rubber lip off. You can usually hook the top or bottom and then snap them over one way or the other without bending them up.