Hard Reset LG E450 Optimus L5 II

First method:

1. Power off your device.
   
2. Next press and hold Volume Down + Quick button + Power button.
   
3. Release all buttons when LG logo appears

Second method:

1. First make sure, that your phone is on.
2. Then from the Home screen tap: Settings -> Back up and reset -> Factory data reset -> Reset device -> Delete all.