1.Power off your phone
2.Press together volume up and Volume Down then press power button
3.Select Recovery mode with taping the manue button as shown in picture.
4.Choose with volume buttons "wipe data/factory reset" and select it with manue key
5.Choose "yes delete all" with volume buttons and select it with manue button
6.Select "reboot"
7.Wait until the phone restarts
2.Press together volume up and Volume Down then press power button
3.Select Recovery mode with taping the manue button as shown in picture.
4.Choose with volume buttons "wipe data/factory reset" and select it with manue key
5.Choose "yes delete all" with volume buttons and select it with manue button
6.Select "reboot"
7.Wait until the phone restarts