Before you peform this unlock you must remove the sim card and sd card or it will not reset!
With the phone turned of, press and hold the VOLUME DOWN button, and then briefy press the POWER button.
Wait for the screen with the 3 Android images to appear, and then release the VOLUME DOWN button.
Press VOLUME DOWN to select CLEAR STORAGE, and then press POWER.
When asked to confirm, press VOLUME UP
Restore settings and contacts from the sd card and you're away!