This hinge pin extraction application was shown to me many years ago by a builder. It solves the front extraction hold-down dilemma with a novel approach. The following would be done on a cowl with the hinges already installed. If the hinges are being installed, the last barrel location (top or bottom hinge) does not matter. Start by identifying the last two overlapped hinge barrels; they must remain intact. Three total barrels must be cut off the hinge set.
Counting from the aft end of the hinge, remove the third, fourth, and fifth barrel.Removing the barrels in place is tricky, but a Dremel with a cutoff wheel will do the trick.
Once the barrels are cut, the cowling notch has to be opened inline with the hinge pin. This notch is only the length of the hinge that had one barrel cut off. The net result is an area that would have had three barrels (two and a center) engaged. In the photo, the top is this area of the hinge.
The hinge pin needs to be bent in a fashion that allows grabbing it from the outside, sliding it forward, and pulling out while sliding it aft to remove the pin. The bend in the mockup shown here is slightly small to grab with fingers, so a pair of needle-nose pliers were required. Remember the thickness of the cowl, and make the bend larger to extend outside the cowl more. It is important to have the front and rear of the bend remain inline so the pin engages the barrel correctly. If you are slightly off, the angle can be tightened or opened a tad, and then straighten the shorter, aft part of the pin to align with the rest of the hinge pin.
