Please refer to the manual that comes with your kit for specific installation instructions. Stand at the end tree and hold a 4 FT Carpenter’s Level like a rifle.  Holding one end up to your eye, point the opposite end at the base of the starting tree, right where the dirt and tree meet. Make sure the bubble is between the two hashes indicating level (crouch down if your yard has a minimal slope or climb a ladder if your yard has lots of slope).  Once you have the level aiming at the base of the starting tree, measure from the Carpenter’s Level down to the ground.  This measurement is your natural elevation change. If you have questions, please do not hesitate to give us a call at 541-916-4461