Things You'll Need
Instructions
Connect the external hard drive to your PS3 via the USB cable.
Go to the ̶0;Settings̶1; tab in the Cross Media Bar and select ̶0;System Settings.̶1;
Find the ̶0;Backup Utility̶1; and press the "X" button to select it.
Select ̶0;Back Up̶1; and select your external hard drive as the drive you wish to save it to. All of your game data and game saves will be backed up to your external hard drive.