1. Download the latest ROM upgrade zip package from the specified server.
2. Copy the ROM upgrade package to the phone storage.
3. Go to Settings -> About device -> Version -> Click Build number 7 times and enter the password, now you are in the developer mode.
4. Go back Settings -> About device -> Up to date -> Click the top right button -> Local install -> Click on the corresponding installation package -> Extract -> Upgrade -> System upgrade completed to 100%.
5. After the upgrade is complete, click Restart.
6. Update successful.