Things You'll Need
Instructions
Log in to your Xbox Live silver or gold account.
Cycle through the dashboard using the left joystick until you find the "Games Marketplace" tab and press "A" to select it.
Choose the most appropriate filter option for the type of game you are looking for.
Search through the game listing until you find a game you would like to purchase.
Select the desired game then chose "Purchase Now" from the dashboard. If you do not have enough Microsoft points for the purchase the dashboard will prompt you to purchase more.
Choose to download the game to your hard drive by pushing "A" in the download management screen which will pop up. This will cause the game to download to your Xbox 360 through your dashboard.