I have a question about this ring thing, that stops the handlebar from completely turning (visible at 2:47 for example). In your other video, this thing seems to be broken, is that the case? Cause it is for me and I would like to change it, but I have no idea how, because it seems to be fixed to the scooter and I don't want to use force to change it. I would just leave it, but for me the handlebar feels pretty unstable. Good video though!
It's called bearing cup with a stopper, simple you just hammer it our from the other side. There is a special tools I guess, but i always hammer it out. Yes if it's broken your handlebar will spin 360, so it's not good for the wires.. if you accidentally fall.. it's costs like 5 dollars on AliExpress.
Quick update: thanks to your tip, I managed to replace the bearing cup, but now there are tiny gaps between the cups and the parts they are attached to (1mm gap on the fork and even less on the other one), so my first question is, if this is normal. The stem is also really unstable but i can't tighten the screw on the headset more, otherwise I can't move the handlebar properly. I have tried basically everything and I am running out of ideas so maybe you have a fix for this. Thanks in advance!