Here are the steps you can follow to install Global ROM to Chinese Version Xiaomi Mi 11. It is worth mentioning here that all your data will be lost.
The first step involves updating China ROM to the latest through the updater app first. You then need to unlock your bootloader using the Mi Unlock tool.
You can download the ROM zip file by following this link. Windows users can right-click on the downloaded zip, then go to Settings, and then click on Unblock zip content. Now, you can unpack the downloaded zip file on the PC.

The next step requires you to reboot your device to fastboot mode by pressing volume down + power. Now, connect to PC via USB cable and run fastboot installation script from unpacked zip based on the operating system your PC is running on.
For Windows OS ./windows_fastboot_first_install_with_data_format.bat
For Linux ./linux_fastboot_first_install_with_data_format.sh
For MacOS ./macos_fastboot_first_install_with_data_format.sh
After reboot, it is done. Note that the first boot takes up to 15 minutes.
Installing update of xiaomi.eu ROM
Following these steps will not delete your data and files on internal storage.
First off, you need to download ROM zip file WEEKLY or STABLE, and then unpack the downloaded zip file on the PC. Press volume down + power buttons to reboot your device to fastboot mode. After connecting to the PC via USB cable, all you need to do is to run fastboot installation script from unpacked zip according to your PC’s operating system.
For Windows OS ./windows_fastboot_update_rom.bat
For Linux ./linux_fastboot_update_rom.sh
For MacOS ./macos_fastboot_update_rom.sh
It is done after reboot. Note that the first boot may take up to 10 minutes.
Update via OTA
Installation via OTA is currently not possible because of missing TWRP. The updater will notify you when a new version is available and download it to your device. After copying it to your PC, you need to unpack it and run the fastboot_update_rom script. Check out the video for an update guide.