Problem! Back to MIUI from CM13 with unofficial unlocked bootloader!

Hi guys,

sorry for my bad english.

I have a problem. I have unofficial unlocked my bootloader, install TWRP and then CM13 from Santhosh M.

I'm very happy with this ROM, but now i can official unlocked my bootloader and i will try out MIUI from xiaomi.eu.

Please were can me say how i can back to original MIUI ROM, unlocked my bootloader official, install TWRP and then MIUI from xiaomi.eu?

I'm very happy about your answers!

Greetings from germany
Ben