Instructions
Connect the USB drive into the USB slot on the PS3. Press the "Eject" button on the PS3 to open the disc tray. Insert the game into the disc tray. Press the "Eject" button again to close the tray. The game system then loads and takes you to the system's "Main Menu."
From the "Main Menu" select "Settings" then select "USB Connection." Find the mod file you want added to your system, select "Move" and press the triangle button on the video game controller.
Select the PS3 Hard drive as the destination for the move. Confirm the move and wait for the file transfer to finish. Restart the system and play the game. Once the game loads, taking you to the start menu, select "Downloadable Content." Choose to open the hard drive and select the mod file you want added to your game. Once you add the mod to your game, go back to the "Start Menu" and start the game.