Measure 0.75 inches in from the trailing edge along the wingtip and make a mark. Measure 1 inch in from the wingtip along the trailing edge and make a mark. From this mark, measure and make a 1 inch line inwards from the mark you made along the trailing edge. Once this line is made, connect its edge with the mark on the wingtip. Proceed to cut along this line.
After these cuts have been made, tape the airfoils of your Simple Omniwing at their rear edges as shown.