Copy the firmware files to the root directory of your USB drive. Do not put them in a folder.
The process usually takes 5–10 minutes. The unit will reboot several times. Do not touch the screen or pull the USB out until you see the Android home screen. Troubleshooting Common Issues yt9260ver11 firmware free
This is a Russian forum that is incredibly deep with technical resources for Android head units. (Use a browser translator to navigate). Copy the firmware files to the root directory