Instructions
Press the "Xbox" button on the Xbox 360 controller to open the Xbox Guide menu. The "Xbox" button is the gray button with a green "X" icon in the center of the controller.
Press the "Y" button on the controller. This is a shortcut button for the Guide menu. It does not matter what option is highlighted in the menu.
Press the "A" button to confirm the prompt that asks if you want to return the Xbox Dashboard menu.