All I did was to make a slot about one inch long by 1/4 inch wide (approx. sizes) directly above the servo arm pivot point. I had to sand a slight groove between this slot and the aileron horn for pushrod clearance. CA the aileron horn on top of the aileron directly in line with the 1 x 1/4 slot. Install the servo arm on the servo with the arm sticking up through the slot, connect the pushrod and attach the servo to the foam wing - I used GOOP on the servo. That's it.