You move your turret knobs in the direction you want your bullet impact to move. If your impact is right of where you aimed then turn the turret to the left and the point of impact of the bullet will move to the left.
The same logic follows for the elevation adjustments.
If you wonder what the crosshairs are actually doing when you do this then, with the gun solidly held in position and the crosshair on your aim point, turn the elevation turret a long ways in the up position and watch the crosshairs.
novaman64...I see you changed it. Good catch.