1. Backup your device.
2. Follow the prerequisite steps here
3. Open the Phone app and type *#*#2432546#*#*, do not hit call
4. Enable 'Allow OEM unlocking' under 'Developer options' in Settings. You cannot proceed if it is greyed-out/disabled.
5. Reboot to the bootloader: With the device powered off, hold Volume Down + Power.
6. $ fastboot flashing unlock
7. Reboot the device, then reboot back to bootloader
8. $ fastboot update divested-18.1-20230918-dos-marlin-fastboot.zip
9. Reboot to the recovery: With the device powered off, hold Volume Down + Power. Then use the menu to select *Recovery Mode*.
10. Choose "Apply update", then "Apply from ADB", and $ adb sideload divested-18.1-20230918-dos-marlin.zip
11. While still in the recovery perform a factory reset
12. Reboot into DivestOS. If it takes more than 10 minutes to boot then something is wrong. Do not let it sit for more than 10 minutes!
13. There are monthly updates. You MUST read the News page and backup your device before each update.