If the stripe kit was manufactured correctly, you should be able to just set the pre-cut strips over the belt line molding and use that as your line all the way down the car. The photo above in the right corner will show you how high it is supposed to be above the line. You will also need a thick bondo spreader to go over the top of the kit and squeeze the air bubbles out before you peel off the top strip. The stripe will still have a few bubbles, but leave it out in the sun and a lot of them will disappear. Get a needle and your spreader, pop the bubbles and work the air up past the top or bottom of the stripes. It isn't fun, but the end result is great.