If you want to impact lower you need to move the dot lower, if you want to hit higher you need to move up. I re-read your question, which is a little tricky the way its worded. If you are 3" high & want to move down you take the top turrent knob off & dial it down the desired amount & reshoot to check your adjustment. Same thing for left & right, if you need to move left you dial the correct amount to the left.
Dick
