As you know Xiaomi smartphones runs MIUI, a modified OS based on Android. In case you have to do a Factory reset on your mobile, after booting up, you will be asked for your Google Password and MIUI Password. This is done for security reasons, in case someone steal your mobile. But what happens if by any chance you forget the password!? How can you perform Factory Reset, without been asked after that your MIUI password!?
First of all, you must have an unlocked device and installed TWRP or CWM. How you can do that, we have mention it before, at least for the TWRP. Now, all you have to do is to reboot in recovery mode and enter in recovery. To do that, other you do it from the Upgrade Program, used for receiving the OTA or you can do the following :
1. Turn off your device by long pressing power button.
2. Once the device is completely turned-off, press & hold Power + Volume Up buttons together until Mi logo is appeared on the screen.
3. Now with the help of Volume button, navigate to the option “English” and then use the Power button to select.
4. Tap on Wipe & Reset > Wipe all data.
5. Confirm the data wipe by selecting Yes.
6. Once done, you need to go back to recovery main menu and choose Reboot.
Take care that this will delete ALL your data. This means images, video, programs, contacts, everything! So before you do that is good to have taken a backup. Also this is the way to have a brand new mobile.