I need to delete my ipod 4th gen from my account how do i do that ???
You need to unassociate it from your account. See:
iTunes Store: Associating a device or computer to your Apple ID
What do you mean "delete" it?
I have a new ipod 5th gen and do not need the 4thgen anymore
You need do nothing.
Plug in the new ipod and sync it
Retrieving data ...