Instructions
Turn off the console before attempting to install a hard drive. Stand the device on its end so that the hard drive bay is at the top of the Xbox 360.
Place the hard drive over the hard drive bay. The narrow end should be pointed toward the front of the Xbox 360 and the broad end should be pointed toward the back of the system.
Push down on the back of the hard drive. Line up the back of the drive against the ridge on the back of the hard drive bay. Also line up the connector located near the middle of the hard drive and the hard drive bay.
Push down on the front of the hard drive until you hear a click.
Remove the hard drive by first turning off the console. Then, press the tab on the front of the drive as you lift the device off the top of the Xbox 360.