For sights that don't have 2nd axis adjustment I hang the bow from a hook with a string and plumb hanging from the bottom limb and make it perpendicular to the floor. While doing this and making sure the bow is level with the plumb and see if the bubble level on the sight is correct. If it isn't I will use adhesive silencing foam or felt to shim the sight until it is level. I like doing this anyway because it will help eliminate vibration. This will get your 2nd axis level. To do 3rd axis you need a sight that has that capability.