Well, if you are trying to change it forever, then I suggest contacting your hosting company and asking them.
If you are simply trying to mask your IP on various sites, then I would simply use an anonymous proxy server.
By connecting to a proxy server, the web sites you visit will read the proxy server's IP and not your own.
I used to use a program called
MultiProxy.
MultiProxy Tutorial
Only problem with MultiProxy is the proxy lists are outdated.
Simply go to Google and enter
fresh anonymous proxy servers
Hope this helps.