How can I unlock my iPod nano if I forgot the "Screen Lock" code?

How can I unlock my iPod nano if I forgot the "Screen Lock" code?
"Screen Lock" is provided by the iPod nano, iPod (5G), and subsequently released iPod models. Earlier iPods do not offer this feature.
Screen Lock only locks users out of the user interface. It does not encrypt data on your iPod. For example, if you use Screen Lock and then connect your iPod to a computer, you'll be able to manage music on your iPod with iTunes and access all data on it in disk mode (contacts, notes, and any other files you have stored on the iPod).

Removing Ipod lock has two different ways. First one is Restoring your Ipod Software using itunes or just doing a little trick using your primary computer.

Option 1:

1. Connect your Ipod to your computer.
2. Click on Tools/Folder Option/View/ Check the “Show Hidden Files”
3. Select the Ipod Drive/and Find the filename like "_locked"” inside your Ipod.
4. Delete that file and Disconnect your Ipod from your computer.

If you can't unlock your iPod and you don't have access to the primary computer, your only option is to restore the iPod, which will erase all music and data. Make sure you have the latest Itune software which can be found here.

Option 2:
1. Connect your Ipod to your computer, on the Itunes main Menu Click on Restore Ipod.
2. 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.
3. Connect your iPod to the computer that you want to be the primary computer.
4. Open iTunes and synchronize.