Guy, I'm on work right now and can't explain in details, I'll try to resume what I remember and if even that way you can't figure out latter at home I can try to describe step by step, basicaly is about it:
Step 0) I forgot about it, make a backup of your everything.
Step 1) Download:
ADB/Fastboot (I got it from some of the links on the other thread)
The rom 6.1.7 (Or the right version from the link to unlock it, I don't record the number)
MiFlash (It seens to be a xiaomi program to flash roms)
The TWRP Recovery (This one I think I got from some link on google, just search for TWRP MI4c and you will find it)
The EU MIUI rom that you want to use
Step 2) Install ADB and Miflash programs.
Step 3) Rename the TWRP file to something easy to type like "twrp" you will need to type it on a DOS windows.
Step 4) Now following the tutorial to unlock without xiaomi you will start your phone on fastboot It's just about turn it off, and turn on pressing volume down together. The device should turn on with only a animal with a hat fixing the green android and "fastboot" below both.
Step 5) Copy and paste the TWRP file to the ADB folder.
Step 6) connect the device on fastboot mode to the PC
Step 7) Press shift on the PC and right click inside the ADB folder like when you will create a new folder. but instead you will choose "open a command prompt here" or something like it.
Step 8) you should enter the tutorial command on ADB "fastboot blablabla don't remember the command"
Step 9) now you should follow the tutorial i don't remember the exacly thing but is about turn on the device on a totally black screen like he is dead
Step 10) still following the tutorial you open the MiFlash program and click on "browse" so you should search for the rom 6.1.7 and them click on flash.
Step 11) Start your phone normally like you would use it (i even configured it to the point i could use the android, just to make sure)
Step 12) Follow the tutorial i don't remember but I think is about to fastboot again the device conect to pc and use another command.
Step 13) now you have the unlocked bootloader, you will again use an ADB command to instal TWRP.
Step 14) Start TWRP you again can use a ADB command to do this or if I'm not wrong volume UP + turn on will get you there
Step 15) Go to wipe and clean everything.
Step 16) put the desired rom into the phone using your pc
Step 17) on twrp choose install e search for the rom on the folder you passed it.
Step 18) Be happy and have a beer.
For now It's what I can remember, hope it help you, if it's not enough sorry, let me know and latter I can try to help you more.
