Quick and simple way, make a box the shape of what you want to cut out making sure it passes thur the wing, then select your wing and do a Boolean, Cut and Refine with the box as the second operand. After the cut, convert the wing to an editable poly or mesh and clean up and excess points. If you use the box as a Reference, it will help guide you to see the excess points. Next you can mirror the box and then move it to the opposite wing to cut it. When finished you can delete the box or reshape it to make another cut. Usually I just work on one wing and then mirror the whole wing to the opposite side when it is complete then detach my cuts.

Lou