If you REALLY want to change your IP address, try calling your ISP (the company you get Internet service through), and tell them that a repairman recommended resetting your address through them. They'll walk you through it (at least they have for me in the past, but I was calling because my repairman really said I should do it, so I can't guarantee anything).
Actually you can change it. All you have to do is unplug the power source (at least 24 hours) and your current ip will go back in to a pool and you should recieve a different one. I did this with my broadband connection. Good luck!