Yes you can upgrade the HDD but you will require a few other parts as well. The 60/80 GB are thicker drives. You will require a deeper rear panel, a new head phone jack since the cable has to be longer as well as a new battery for the same reason You will also need the rubber bumpers from the bigger drive as well. The 30 will not fit. I think that is it and should be a complete list. Good Luck to you and your ipod.