Instructions
Insert a USB flash drive or external hard drive into one of the USB ports on your PS3 console. Turn on the PS3 after inserting the flash drive and wait for the menu screen to appear.
Go to "Settings," "System Settings" and "Backup Utility," then select "Back Up." Press the "X" button on your controller to begin the backup process. Wait for the backup process to complete, which may take several minutes. Remove the USB flash drive from the PS3 after the backup has completed.
Insert the USB into the PS3 you want to transfer your theme to. Go to "Settings," "System Settings" and "Backup Utility," then select "Restore." Press the "X" button on your controller to restore the data saved in the USB flash drive to the PS3. Wait for the restoration process to complete, which may take several minutes.
Go to "Theme Settings" and "Themes," then locate the theme you want to install. Press "X" on your PS3 controller to install the theme. Your theme will now be displayed.