Mount a appropriately powerful servo in the wing root, then use a torque tube down the length of the wing, mount an arm on the end of the torque tube, then a pushrod from that to the aileron.
Take a look a Servo City for ideas
https://www.servocity.com/servos/ser...ments/couplers
https://www.servocity.com/servos/ser...chments/shafts