The mag factor is set by first entering the mag factor calibration step as described above. The leds will show the present mag factor. There are only 4 levels of mag factor.
If the central joystick is pressed down and held down while the stick is moved left and right, the mag factor leds will change to indicate the new value. The central joystick is released while the correct mag factor is displayed to lock in the new mag factor. You must hold the pressed joystick in position while lifting your finger to get the new valur to lock in.