Instructions
Turn your PS3 on. Select the "PlayStation Store" option in the PS3 main menu.
Select the "Add-Ons" option in the PlayStation Store main menu to bring up a list of games with available add-ons. Select the "Little Big Planet" option.
Select the "Kratos Costume" option in the next menu, then select the "Download" option to begin downloading the add-on. If you do not have enough funds in your PlayStation account, you will be asked to add more. Use the information on your credit or debit card to add more funds to the account, after which the download will continue.
Exit the PlayStation Store after the download is complete. Insert your "Little Big Planet" game disc into the console to begin playing. The game will automatically detect that you have downloaded the Kratos costume and allow you to use it.