Turn it off;
Tap and hold: Volume Up, Home, Power – all at the same time;
Let go of the buttons when you see the Android icon;
Select your option with the Volume Down;
After highlighting the Factory Reset use the Power button to activate it;
Use the same two buttons to select and activate the confirmation option “Yes – Delete All User Data”;
Just wait for the smartphone to reboot with a clean memory and no password left on it.