You can ' backup' b/c passcode rmb that! & it may take hours if a new software has been released depending on your Internet connection!
You can skip back-up and go straight to downloading and restoring your iPod however if there is a software needed for update.
Patience is virtue if your connection is playing foul.. . Go to apple or wait out your download b/c you need the new software to be updated before it can be restored to its default settings
Remember to make sure you have the lasteat version of iTunes before you start downloading the software OR you may be force to start all over !!! -.-'
If this doesn't work and you don't have much patients in figuring out how to solve the whole problem than I suggest asking an apple employee at ones of their retail stores ^,^
- Connect to iTunes