Pattern Lock
1. Turn off the device. If its stuck then try to pullout the battery for a minute and then put it back in.
2. Press down the home key and the power key.
3. Then release the power button after Logo appears.
4. Now a menu appear give you the options to Fastboot, Recovery, Clear Storage and Simlock. Select Clear Storage. use the volume down button to navigate the menu.
5. Then press and release the power button.
6. Finally wait for your device to reboot.
