1. Flashing full MIUI ROM pack on the phone
Download necessary files to prepare for flashing MIUI ROM
Flashing a newer version of MIUI ROM doesn’t need to wipe data, but flashing an older one does.
Download the latest MIUI ROM Download Now
If you have downloaded the latest installation pack, there is no need to download it again.
Connect your phone to the computer, and put the ROM file to the folder downloaded_rom in the SD card. Open Updater on the launcher, press the Menu button – Select installation file. Choose the ROM pack you want to flash, and select Update now.
After updating is completed, select Reboot now to enter the new system.
For Stock Rom Xiaomi here