The only software that I used and happy with it is the Tor Browser. Download it and enjoy browsing like never before
Yes, the use of a VPN is the unique safe way to change ip and block your isp to see your internet traffic. Hide My Ass have a nice Auto IP Change feature if you want change ip automatically periodically, if you live in north america, I suggest you the site www.topvpncanada.com they have a nice list of vpn providers with complete reviews & how-to guide (if you are noob )
I suggest you to use VPN. I have used HMA! pro. It is good. KickAss is also a good software. If you want to change IP for free then you can do it with your browser. But it is not so effective.
http://www.hotspotshield.com/ It is one of the most widely used proxy changer software throughout the world. It has the ability of supporting 15+ languages of the world.
I would not suggest that http://hideipaddressonline.com/what-is-a-private-ip-address/ Here are some reasons why you should Hide you're IP address http://hideipaddressonline.com/hidemyass-software-review-surf-the-internet-anonymously/ so you can browse anonymously nothing beats HIDEMYASS SOFTWARE
You can try Tor Browser if you need it only once or twice. If you frequently need to have different IP you can 1. Use some VPN service or browser extensions. VPN often is paid. 2. Use proxies. They can be free but didn't get you good browsing speed mostly 3. You can rent a Linux server for a few hours and setup your own proxy out of it using SSH tunnel. I'd personally prefer that, it's very quick and should take 3-5 minutes tops. Take a look here for the article about that: https://serversuit.com/community/technical-tips/view/things-to-do-with-ssh-ssh-tunneling.html