Instructions
Turn off your PS2. Connect the USB end of the PS2 keyboard's data cable to the USB port on the front of the PS2 console.
Press the "Eject" button on your PS2 to open the disc tray and turn on your PS2. Insert the game disc into the PS2 game tray and close it. The PS2 should automatically detect the game, allowing you to begin playing.
Test the keyboard by playing the game until you are prompted to type, then use the keyboard. Since the keyboard drivers are already installed in the PS2 hardware, the keyboard will work automatically.