Start by flashing the latest BSP and L4T image onto the tx2. At the time of writing that was Ubuntu 18.04 based. Will need a monitor for initial setup - networking will also be necessary
Once installed
- Purge chromium browser and all components
- update and upgrade
- autoremove any packages
- remove nvidia jetson and connectech orbitty BSP from apt sources list to prevent further updates
- reboot
- modify /etc/update-manager/release-upgrades and change when updates are offered from never to normal
- update and upgrade again
- sudo apt-get dist-upgrade
- sudo do-release-update