Loosely assemble the entire ladder and pick a good spot where you would like to place the ladder. Make sure the ladder is on the side of the van without the sliding door. Using a friend, hold up the entire ladder and mock it up. Stand far away from the van to see what looks most aesthetically pleasing and mark the holes both at the top of the ladder onto the side of the roof rack and mark the holes underneath the van on the pinch weld. These markings will be where the ladder mounts, so make sure your ladder is straight and aligned properly. After you've verified and marked where the ladder is going to be mounted, drill into the side of the DRIFTR rack and into the pinch weld at the bottom of the van. Install and fasten bolts on the top and bottom of the ladder, then push the middle ladder in or out to set the distance from the van to the ladder and tighten the 4 bolts per side of the ladder. Double check all bolts are tight, and you're good!