Step 1: If the device is on, switch it off
Step 2: Press together and hold the Home button and down volume buttons (the HOME button can you find in the front side, under the screen, this button has a picture of a house. The down volume button can you find on the right side of the Smartphone).
Step 3: Press and hold the Home button and down volume buttons until 10 seconds.
Step 4: Now press and hold the power and volume up button while keeping your hold on the volume down button until the factory reset screen appears, release your hold on all buttons
Step 5: To complete the hard reset, release all the buttons.