Instructions
Power on the PS3 and wait for the main menu to appear on the screen. Press the right directional arrow button until you reach "PlayStation Network."
Select "PlayStation Store."
Choose "Games" and select the game you want.
Select "Buy Now." You will be asked for your billing information. Enter your credit card data.
Press the circle button until you exit the PS3 store. Push the left button until you reach "Games."
Push the down button and find the game you just downloaded. Press "X," and the video game will install onto your PS3.