Kugoo Kirin S1 scooter ERROR 40 REPAIR. Also brake/screen/throttle/battery/control box repair guide

Error 40 on my scooter, so have recorded the repair process.
You can also use this guide to as an brake/screen/throttle/battery/control box repair guide
Battery dies whilst making the video, apologies.
To fix the error, you are replacing the brake throttle with a new one. 👍