Instructions
Turn on your PS3 console and press the middle ̶0;PSN̶1; button on your controller.
Select the first option in the list (the option is ̶0;Settings̶1; in English) and then select the first option in the next list (the option is ̶0;System Settings̶1; in English).
Scroll down to the ̶0;Language̶1; icon and select ̶0;English̶1; from the list of languages. Confirm the change when prompted and return to the main menu. Your PS3 and PSN language has now been changed from Japanese to English.