You don't actually need the same computer that you've used in the past. I've done a lot of these on my computer and they were never hooked up to that specific computer before. Just open iTunes on any computer. Turn your iPod off. Hold down the home button while plugging in the cord to connect it to the computer. Keep holding it down until you see a cord on your iPod. iTunes will ask you to restore, do so. You're all set, but you're going to loose all your data.