You can't change your IP most likely.
Your provider probably marries the IP address to the specific MAC address of your cable or DSL modem, so even if you killed everything for a week or more, you'd still get the same IP address. It's not truly static, but it may as well be.
If you get a new modem, it's possible that they would change your IP, but the only way to be sure is to change to a different ISP.