First I determined where I would drill the holes. I knew I wanted the pins located in the flat area where the bumpers landed and I wanted to accurately place them symmetrically. Measuring was iffy without any obvious centerline and with the curves of the body to each side angled that wasn't as precise as I wanted to be. First I tried putting caulk on each bumper and while doing so noticed a hole in the center of each perfect for a screw or bolt or some kind of poker. A screwdriver bit fit perfectly:
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and with a little dab of caulk left a precise mark:
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The left and right marks were not exactly the same so I picked the one that was most centered and repeated the measurement on the other side. I drilled a 3/8" hole on each side and installed the pins:
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BTW if you ever need to remove the OEM bumpers - they screw out:
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Looks good:
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Dabbed more caulk on the ends of the pins to determine where to drill the underside of the hood. I just had to enlarge the hole for the OEM bumper slightly and then repeat to mark the underside of the hood. Once marked I drilled a 1/8" pilot hole corresponding with each mark from underneath, then finished with a 1/2" hole drilled from the top. I taped off the area well to protect from damage and prevent chipping around the cut lines.
When I purchased the Aerocatch hood pins I also picked up a pair of flush mounting plates from Password JDM. They're aluminum and replace the plastic Aerocatch plate that goes underneath. I used the provided templates that came with the plates to mark the latch opening cuts:
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I wanted to be sure they were aligned symmetrically so I took plenty of time to just sit back and look at the layout. They were real close but the right side didn't seem right. In the end I used the paper templates that come with the latches to mark centerlines, then extended those line as far as I could. Using a flexible straightedge I extended the lines to the front edge of the hood and made a mark with a white grease pencil. I measured from the corner of the hood along the front edge to the mark from each side and determine the right side was about 1/8" or so off so I rotated the template and remarked the tape. Satisfied I had the alignment I used double sided tape to secure the mounting plates as a guide for my router and a flush cut bit. You can see the grease pencil marks along the edge of the hood:
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The flush cut bits I had would have worked fine if I had placed a spacer to elevate the plates above the hood but I'm too impatient so I decided to use a Dremel and cutter bit to go inside the opening leaving about 1/16" of material. I used a sanding wheel to remove this material flush with the plates - it took a little of the anodized finish off but that will never be seen. I'd definitely use the spacer and router if I were to do it again but I'm a perfectionist. I used the holes in the plate to drill 1/8" pilot hole for the screws:
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It came out nice. Notice I used the plastic the hood shipped in to cover the engine. Carbon fiber is electrically conductive (brushes for electric motors are made of carbon) so you don't want it in your engine electrical or in your electric tools - use air if you can.
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Then I drilled out the holes to their finished diameter 5/32". Be sure you place tape over the holes to prevent chipping (voice of experience) and step up in bit size(1/8", 9/64",5/32), not skipping sizes, to ensure clean holes. Be prepared - the pilot hole will suck your bit into the cf before you can blink. If you go straight to the final bit size you may break the material between the cutout for the latch and the hole 'cause it ain't much. Notice the one hole that's chipped. In retrospect if I had drilled the holes before cutting the opening it would have eliminated chipping and tearout so that's my recommendation.
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Next I installed the rubber bumpers and marked the underside of the hood to clear with a 1 1/2" circle, then trimmed it with the Dremel:
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Installed:
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