few ways to get new ip from ISP;-
1. disconnect from network from ISP, wait for x mount of time, then reconnect again and hope you get new ip.
2. disconnect from network from ISP, change your own mac address, then reconnect again and hope you get new ip.
3. use proxy server to change outbound ip.
4. use reverse proxy server to change inbound ip.
5. use VPN to change ip.
6. use SSH Tunneling to change ip.
7. use tor (www.torproject.org/) to make ip address fly ( ip address changed at every call)
The list should be much long, but I only list common one.