Instructions
Turn off your Xbox 360.
Position your Xbox 360 vertically with the USB ports at the bottom.
Remove the hard drive bay cover from the top of the Xbox by pressing the release button at the top of the system. This will reveal the open bay that connects to the hard drive. You also should see a connector that attaches to the hard drive.
Set the back of the hard drive into the top of the Xbox first. This is the wider end of the hard drive.
Place the front of the hard drive down until the hard drive is attached to the connector port and the release button snaps into place.
Turn on your system. Your new hard drive will be recognized right away.