English instructions for packing yor Xbox. I won't write them out here, as the resolution on the photo is just high enough that you can read it yourself if you care.
The short form:
Take off all accessories - including HDD, faceplate, cables and wi-fi antenna.
Remove any disks in tray.
Put in bag, put foam pads on ends of Xbox.
Put in box, reseal with included tape.
Attach included shipping label over top of original label.
Take to Purolator, or call them for pick-up (you have to pay for pick-up if you want it).