Things You'll Need
Instructions
Place the Forza 3 Disc 1 into the Xbox 360 console disc tray and press the "Insert" button.
Press "Y" on your Xbox 360 controller to bring up a new menu. Select "Install Game" to start the automatic installation.
Press "A" to play Forza 3 once the installation is complete.
On the menu screen, select "Install Disc 2." Eject Disc 1 and enter Disc 2 into the disc drive once prompted. The process to install Disc 2 can takes 10 to 15 minutes as it contains 1.9 gigabytes of gameplay graphics, including several unlocked cars and racetracks.