Q: how do I reset the 4 digit pass code on an ipod?

Hello crazyquilt0204,

If you don't remember your Screen Lock, you will need to restore your iPod.

iPod: How to use the Screen Lock - Apple Support

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:

 

1. 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.
2. Connect your iPod to the computer that you want to be the primary computer.
3. Open iTunes and synchronize.

Note that article doesn't mention the iPod classic specifically, but it applies to that as well.

Thank you for visiting Apple Support Communities.

Nubz