ipod is locked dont remember passcode,how do i get it unlcoked?

If you cannot remember the passcode, you will need to restore your device on the computer that you Usually Sync with...

See Here

http://support.apple.com/kb/HT1808

Wrong Pass Code

http://support.apple.com/kb/HT1212

Connect the iPod to its syncing computer and restore via iTunes. Place the iPod in recovery mode if necessary. For recovery mode:

iPhone and iPod touch: Unable to update or restore