Download the ROM from the file location as per the weekly ROM updates directly to your device storage.
Go to the settings/system update section and click on "reboot to recovery"
Install the latest ROM from recovery
Wipe Dalvik
That's it!
Sometimes the bottom half of the home screen is missing. It's completely blank. You have to start an app and then go back to home for it to recover.
Mi Mix 2S on 8.11.15