how do i changes the administrator settings to sync my ipod i bought used?

You have posted in the iTunes for Mac forum. If you have a Windows system as your profile line states, you'll probably get the quickest and most applicable responses if you post in the iTunes for Windows area. When you repost, you'll probably need to explain in more detail what you are trying to accomplish and/or where you're running into difficulties, as to me at least it's not clear what "administrator settings" you're asking about.

Regards.