Things You'll Need
Instructions
Press the Xbox button on the Xbox 360 controller. This is the gray button with the green "X" in the middle of the controller. A menu will appear on the screen.
Select "Sign Off" from the menu. You only need to do this step if you are signing out of one Xbox Live account to sign into a different one.
Go to the Xbox 360 Dashboard menu. Select "Go to Dashboard" from the menu that's opened with the Xbox button.
Scroll to "My Xbox" in the Dashboard menu.
Select the "Profile Sign In" box from the "My Xbox" menu. This is the box with the silhouette of an account avatar on the right side.
Choose the gamer tag you want to use to sign into Xbox Live. The Xbox 360 console will sign into Xbox Live using the gamer tag you selected.