According to the plans, you bevel the aileron in the center of its leading edge. This is shown on the left-hand side of the wing plan sheet. If the ailerons were built correctly, and the material used is the proper thickness, you'll have plenty of aileron throw when you hinge them. If you don't like how they are designed, you may, of course, make any modifications you desire, but they won't be according to the plans, so you may not get the results intended by the designer of the model.

As I stated earlier, if you build according to the plans, and the materials are the correct ones, the model will fly very nicely.