Instructions
Select the "Settings" tab from the Xbox 360's dashboard and then select "System."
Select "Storage" followed by "Hard Drive" from the Storage Devices menu.
Select "Games & Apps" to display a list of all installed games and applications on your Xbox 360.
Select an installed game from the list. The list is in chronological order and you can recognize an installed game by its 4GB to 8GB size.
Select "Delete" followed by "Yes" to delete the installed game from your hard drive.