Hard Reset XIAOMI Mi 2

First method:

• Power off the phone

• Next press and hold Volume Up + Power button.

• When the Mi Logo appears  on your screen release only the Power key.
• Keep holding the Volume Up key until the Recovery Mode appears.

• In this step select English using Volume keys to browse and Power rocker to select.
• Then select "wipe data/factory reset" by using Volume Down to scroll and Power button to confirm.

• Select "Yes--delete all user data". Use Volume Down button to scroll and Power key to select.
• To restart the device, select "reboot system now".

• Success! The hard reset operation has just been performed.

Second method:

1. Switch on your device.

• Afterwards go to Settings and then to Backup & reset.
• Tap Factory Data Reset and selec Reset Device. 
• Choose Erase Everything if you are sure you want to clear all your data. 
• Select OK to confirm the whole operation.
• Well done!
• Xiomi MI3 Hard factory reset