The instructions with the ARMS are very clear and easy to follow, with 2 approaches one way is fitting it inside the cockpit aft of the panel, the other is fitting it into the foam forward of the panel. The approach you use will depend how far away you need to mount the ARMS from your camera lens. I have made this install video to support those users who need to fit into the foam. Although the instructions are clear, the suggestion is to gouge out a hole for the sight with a screwdriver. This will work, but may generate a very jagged hole in your foam, especially where the screwdriver exits the rear of the foam. I use a simple technique that makes a perfectly round hole in foam every time. All you need is a tube the diameter of your hole, and this principle will work.