How to factory data reset an Android phone using Recovery Mode:

1. Make sure the phone is off.
2. Press and hold the power and volume down buttons simultaneously.
3. Continue pressing them until the screen starts.
4. A screen with the word “Start” pointing at the power button, text, and navigation instructions will appear.
5. You can now use the power button to make selections and the volume keys to navigate.
6. Hit the volume down button until you see Recovery Mode.
7. Press the power button to select it.
8. The phone will restart and show an Android robot in distress.
9. Press and hold the power button, then press the volume up button while still holding the power button.
10. Using the volume buttons, highlight Wipe data/factory reset.
11. Press the power button to select the option.
12. Confirm by selecting Factory data reset and let the phone do its thing.
13. Once done, select Reboot system now.