Instructions
Turn the PS3 around so that you are looking at the rear of the console.
Connect the USB DVD drive. Plug one end of the provided USB cable into one of the USB ports located on the rear of the PS3 below the "Power" switch. Plug the other end of the USB cable into the USB port on the DVD drive.
Plug both devices into a power outlet. Turn on the devices. The disc in the USB DVD drive can now be accessed via the PS3's main menu.