I have a Kawasaki ZX1000sx and it has an alan nut on top of the fork, seeing as this mount fits in a round hole, is the small part in the box for a different hole size?
Just wedge a flat head screw driver or something similar under the bottom part and it will come up. Might seem like you’re going to break something at first but that’s highly unlikely
Sorry for the 6-month-old reply, but there's a chance this might save someone some hassle. This setup DOES NOT work on my 2017 CB500F. There are extra raisers above/either side of the fork stem to lift the handlebars (I assume for/because of the more upright riding posture than the CBR). These plus the handlebars themselves block you from fitting the arm/screw at 4:23. Or, if you attach the arm first and then try to mount the whole thing, you can't tighten the part from 3:45 because the same screw (and the cover) gets in your way and the entire assembly sits loosely in the fork stem. I think my bike's previous owner found a middle ground by partially tightening the first piece, attaching the arm first and FORCING it into the tube, but over time it vibrated loose, and I almost lost my phone when I went over a bump and the whole thing jumped up out of the tube. So now I have to research alternate ways to attach it more safely.
2019. This same setup should work on your 2016 I believe. There may be a cap over the spot where the mount will insert. You should be able to remove it easily! Hope this helps