How to back up Xbox360 HHD for NEW Xbox360??

This "question" may have been asked before but I failed to find it even if I have searched for it.
As said above, HOW to backup my son's working Xbox360, which got a lot of paid "Extras" such as Maps and other multiplayer's Maps etc., to an external USB external HDD for temporarily storage. Such that IF my son's existing Xbox360 has gone faulty beyond repair then he could recover ALL his "paid" Extras either by 1) recovering them to a NEW Xbox360 using this external USB HDD which pre-stored all his Extras, or 2) to the extreme that I can even replace a NEW Xbox 360's HDD with this OLD HDD please?
I think the 2nd option is probably not easily workerable as the NEW Xbox360 may be locked into its new HDD's serial no. or signature etc and I have to "open-up" the NEW Xbox360 to do it.However as for 1st option, HOW to pre-format the USB HDD to a "format" that can be recognised by the Xbox360's platform and HOW to back the "selected" data up??

Thanks

I have since found this LINK via Google and it seems to have suggested WHAT I wanted.

Link: http://www.ehow.com/how_6696935_backup-xbox-360-hdd....

Thanks

Just as a note your son can download all his previous stuff if any sort of drive failure were to happen, you can do it from the dash and you can do it from xbox.com

On xbox.com you login > my xbox > account > purchase history and you can queue up your content, really old content like old gamer pictures or really old style dash themes and really [censored] xbla games like yaris might be not available to restore though.

Just a case of going to the System Settings, Memory, Games and copy to the external USB HD or memory stick

I have mine backed up on a 16GB memory stick

http://support.xbox.com/en-gb/pages/xbox-360/how-to/...

Microsoft seems to have thought about that! Apparently my son can do it via the Xbox360 too by logging into his "Account" and downloading his previously purchased MAPs and Extras etc as you have rightly mentioned before. However as for his "saved gaming checkpoints" these would only rely on any backups saved on the external USB drive or memory sticks. Thank for your suggestions.

Edited by deleted (Mon 08-Aug-11 19:47:08)

Yeah! I would need that approach too when coming to my son's games checkpoints as the "Login Account option" previously suggested by another forum user would not work when coming to your only games checkpoints IF they were lost due to Xbox or HDD failures.
Thanks