Q: how do i unlock an ipod nano coming up disabled

Hi lukefromlimavady,

The resource below will explain what to do if you entered the wrong passcode on your iPod nano.  If you cannot access the device in iTunes, you will need to restore it to factory settings and resync with your computer.

iPod: How to use the Screen Lock - Apple Support
https://support.apple.com/en-us/HT201246​

iPod nano, iPod nano (Second Generation), iPod nano (4th generation), iPod nano (5th generation), and Fifth Generation iPod (also known as iPod with video) include Screen Lock, which allows you to set a 4-digit combination to prevent someone else from using your iPod while it is not attached to a computer. When an iPod is locked, you must enter the combination to unlock the screen. 

Locking Your iPod
After you've committed your combination to memory, you can lock your iPod by following these steps:
Select Extras > Screen Lock > Turn Screen Lock On. (If you haven't set a combination, the Set Code screen appears for you to set your combination.)
iPod displays a "Please remember it!" message in the Screen Lock menu; select Lock to lock your iPod.
Once locked, iPod displays an Enter Code screen. You'll also see a key icon in the upper-right corner that tells you your iPod is locked.

Unlocking iPod
You can unlock iPod in one of two ways:
Enter the combination on iPod using the same controls you used to set the combination. If you do not enter the correct combination, the digits onscreen flash red. When you enter the combination correctly, iPod will unlock and return you to the last viewed screen.
Connect iPod to the primary computer you use it with (the first one iPod synced with), and open iTunes. When you disconnect iPod from the computer, it will no longer be locked.

If you can't unlock iPod using either of these methods, you can restore your iPod to factory settings. Please note that this will erase all data on your iPod. Afterwards, you can add your music and data back to iPod.

If you want to change the primary computer that your iPod is associated with, do this:
Restore your iPod. Warning: The restore process cannot be undone. All of your songs and files will be deleted. Always make a backup of your important data.
Connect your iPod to the computer that you want to be the primary computer.
Open iTunes and synchronize.

Take care,