i'm no expert, but i would imagine you would have to connect it and restore it, wiping all data. have you tried plugging it into a computer? it might give you on screen instructions to avoid wiping data (i have not ever done this personally, just taking a guess :P). if there is any precious (photos, downloads, etc) i would reccomend taking it to an apple store as they will be able to give you the best answer.
sorry i didn't really explain too well, i know for a fact that if you restore the ipod you will lose everything if it is not backed up, the rest is an educated guess, so please don't take it as gospel.