- Press and Hold Volume UP + Volume Down + Power key to get Android Recovery Mode.
- Now you see a word "Start"
- Now Press Volume Down for 2 time to see "Recovery Mode"
- Now press power key to enter Recovery Mode
- Now press Volume UP + Power key to get recovery menu in blue color.
- Now select wipe data/factory reset and press power to confirm selection
- Now select Yes -- Delete all user data and press power to confirm selection
- Now reboot device
- hard reset done