Move your iTunes library to another computer
Important: It’s recommended that you create a backup of your library. See the Apple Support article Back up and restore your iTunes Library.
When you get a new Mac, use Setup Assistant (or Migration Assistant, if you’re switching from Windows) to move files—including your iTunes files—from your old computer to the new one. See the Apple Support article Back up and restore your iTunes Library.
Connect computers (over a wireless network or with a cable) and copy your iTunes files from one computer to the other.
Use iPod or a portable drive to transfer iTunes files.