There are plenty of videos about reloading 126 cartridges with 35mm. However, not much about how to get it to work with an Instamatic 134 that uses film advance to cock the shutter. The best way is to reuse the backing paper from the original 126 cartridge and shave off the top sprocket holes.
Scissors in the dark is no bueno. Here's a little device I made to make the process easier and - mostly - safer.
This is merely sharing my idea. If you maim yourself in the dark with a razor blade, I am not responsible.
