Instructions
Memory Unit
Power on the Xbox 360 console.
Grasp the Xbox Memory Unit and pull it toward you to remove it from the console. The Memory Unit is connected to the front of the console via one of the USB ports. It looks like a small white square with "Xbox 360" printed on the top. Do not remove the device when the Xbox is saving or reading data. Doing so may cause data corruption.
Hold the new Xbox Memory Unit with the Microsoft logo facing up.
Insert the device into a free USB port on the front of the console.
Hard Drive for Xbox 360 E and S 250GB
Power off the Xbox 360 and place it horizontally on a flat surface.
Turn the console so its right side faces you.
Find the hard drive cover release switch near the back-right corner of the console.
Move the release switch diagonally toward you, and then open the hard drive door.
Pull on the hard drive's tab to remove it from the slot.
Insert a new hard drive into the slot. Push it in all the way until it clicks.
Replace the hard drive door.