Instructions
Sign into your PSN account. Enter both your user name and password using the PlayStation 3 controller. If your PS3 automatically signs you in, you do not have to re-enter the information.
Highlight the PSN account by scrolling over it. Press "Triangle" and a drop-down menu will appear. Select the "Account management" option. From the account management option, select "Add funds." A keyboard menu will appear.
Locate the 12-digit code on the back of the PSN card. Using the PS3 controller, enter the 12-digit code to redeem and activate the PSN card.