Hold L and press Square, Circle, Triangle at the main menu. The screen will turn black briefly to confirm correct code entry.
Complete all the challenges in challenge mode.
Hold Triangle and press Square, X(2), Circle, Triangle(2) at the game modes screen. The screen will turn black briefly to confirm correct code entry.
Hold L and press Square, Circle, Square, X, Circle at the main menu.
Hold Square and press Triangle(3), Circle(2), L at the main menu. The screen will turn black briefly to confirm correct code entry.