Instructions
Turn on your PlayStation 3.
Open the console's "Settings" menu.
Select "Security Settings."
Choose the "Parental Control" option. Select the "ON" option and choose the level of control you want to use to lock your PlayStation 3. The levels range from 1 to 11, and lower-numbered levels feature less parental locks while higher-numbered levels feature more parental locks. For example, if you choose the level "11" lock, users will only be able to play "E" rated games.
Press "Circle" on the controller to save your lock settings and exit the menu.