Connecting a Hard Drive
Make sure the console is off and place the hard drive over the bay on top of the Xbox 360 console. The narrow end should be at the front of the console and the broad (and rounded) end should be at the back. Place the back down first so that the ridge of the hard drive sits below the lip of the hard drive bay. Push down the front end of the hard drive until you hear a click to notify you it is in place.
Connecting Memory Units
Find the two memory unit ports on the front of the console above the power button. Push a unit into one of these ports until it has no give. If you have only one memory unit you can place it in either one of these locations.
Accessing Memory
Turn on the console to enter the Xbox 360 Dashboard. Go to the "My Xbox" tab and scroll over to "System Settings." Select "Memory" on the next screen to bring up a selection of devices. Choose either the hard drive or a memory unit to access the content on either device.
Manipulating Memory
Select a category once you have chosen a memory device to view. This will open a list that contains such items as "Games," "Videos," Music" and "Demos." Select a category to view the files within them. If you select a file you will be given the option to copy, move or delete a file. This allows you to swap files among your storage devices or to make a backup copy of the files. You cannot make a second copy of a file on the same device -- the copy must be made on a second memory source.