Mark the perimeter of the path using spray paint, increasing the size by 6 inches for the over dig (Image 1). The over dig is necessary to make sure that the outside edges of the stone remain stable during and after the installation. Using your excavator, excavate to a depth of 9 inches (Image 2). If the top soil or any unstable material is deeper than 9 inches, it must all be removed and replaced with modified stone. Compact and stabilize the sub-grade (Image 3). Two passes with the plate compacter should be plenty.