During gameplay, press pause and hold R1 + R2 + L2. While holding these buttons, press CIRCLE, RIGHT, SQUARE, LEFT, CIRCLE.
If that doesn't work, pause the game by pressing Start. Then, press and hold L2. Continue to hold L2, and press and hold R1. Holding both L2 and R1, press and hold L1. Now press and hold R2 while holding the others. Then release them in this order: L1, L2, R2, then R1. Now tap Circle. Press and hold Left, press and hold Circle, press and hold Square, and press and hold Triangle. Release them in this order: LEFT, TRIANGLE, SQUARE, then CIRCLE.