If you really can't remember your passcode, and your willing to loose all your stored content(if you don't use iCloud) reset your device through itunes simply plug it in and hit restore/reset, it will take your ipod back to the apple factory settings. If this fails try this:
Plug in your iPod
Go to "My Computer"
Open your iPod's drive (F for me)
Make sure you can see all hidden folders (If you aren't sure go to Tools, Folder Options, View Tab, and check Show)
Open the folder "iPod_Control"
Open the folder called "Device"
Rename the file "_locked" to "_unlocked"
hope this helps.
Connect the iPod to your computer and restore via iTunes. Place the iPod in Recovery mode if necessary to restore.
If you cannot remember the passcode, you will need to restore your device using the computer with which you last synced it. This allows you to reset your passcode and resync the data from the device (or restore from a backup). If you restore on a different computer that was never synced with the device, you will be able to unlock the device for use and remove the passcode, but your data will not be present. Refer to Updating and restoring iPhone, iPad and iPod touch software.