Instructions
Turn on your PlayStation 3 and wait for the dashboard to load.
Press right on the controller and go to "PlayStation Network."
Press down on your controller and select the "PlayStation Store."
Click on the "Search" button in the top right corner of the screen. Enter "Undead Nightmare" and click "Search."
Select "Red Dead Redemption: Undead Nightmare" from the list of results. Click "Add to Basket."
Select the "Basket" option in the top right corner of the screen and then choose "Checkout." Click on "Confirm" to confirm the purchase. This will deduct the cost of the game from your PlayStation account or the card registered to your account if your PlayStation account is empty. The game will then be downloaded to your PlayStation 3.