OK. Yes, you need an unlocked bootloader to do that.
Before any of the below, you need to set up adb on a computer. (If you don't know how to do this, you're in for a long ride, but you will get there. Search for this on google.)
On your phone enable developer options, and enable USB debugging in developer options on the phone.
As soon as you enable USB debugging with the phone plugged into the computer, ensure you grant permission to the computer that you will use to do this - you will be prompted on the phone.
Right, ready to go?
Here is what you need to do:
1. Unlock you bootloader with the Xiaomi MiTool ( I found a version translated by Francesco Tescari - do a google for his name you will find it).
2.Remove Xiaomi account from the phone
3. Download TWRP 3.2.3 for the EE (Explorer Edition).
4. Download the Xiaomi EU ROM for EE: Find it here: https://xiaomi.eu/community/threads/8-8-23-24.45845/
5. Flash TWRP using the tools in the download, and let it boot to recovery)
6. Format your data partition in TWRP, and flash the rom from your computer using the advanced flash option in TWRP, then ADB Sideload. On your computer, with adb set up, you need to enter the command adb sideload c:\path to the folder where the rom is\Rom.zip
7. Reboot your phone and enjoy.
Roms from xiaomi eu community will not encrypt your bootloader and will not wipe TWRP and replace it with stock recovery on each boot. If you flash an official ROM, both of these will happen.
I can make files available on request.
Is it mandatory to remove Xiaomi account from the phone?