Instructions
Purchase a new Xbox and Xbox Live account card from your local gaming store.
Connect the new Xbox to the Internet using the Ethernet plug on the back of the console.
Put your Black Ops game in the Xbox tray, and start the game.
Choose the Xbox Live option from the main menu.
Follow the on-screen directions to set up a new Xbox Live account using your purchased account card. Make sure to use a different gamer name and email address than the one used on your banned account.