This guide will show you a simple way on :
How to factory reset SAMSUNG Galaxy Grand Max.
How to wipe all data in SAMSUNG Galaxy Grand Max.
How to bypass screen lock in SAMSUNG Galaxy Grand Max.
How to restore defaults in SAMSUNG Galaxy Grand Max.
All method of master reset SAMSUNG Galaxy Grand Max.
So Check out how to accomplish hard reset by hardware keys and through android settings. As a result your SAMSUNG Galaxy Grand Max will be as new and your core will run faster.