Navigate to the /data/system directory.
Tap and hold the accounts.db file, then select Rename.
Rename the file to accounts.db.old to make a backup of the file.
Restart your Android device.
Once the device restarts, open an app that requires a Google account such as Market, Gmail or GTalk. You will be prompted to create a new account or login using an existing account. That’s all there is to it.