How to edit host file

I read in a post that editing the host file will stop vindictus from taking pics of u when u start the boat. but they never explained what exactly needed to be done. Can someone give me a break down please?

Originally Posted by ichigo from another forum
1. Add and block these addresses in your firewall:

avatar.heroes.nexon.com
gamelog.nexon.com
avatar.vindictus.nexon.net


2a. Edit your "hosts" file in "(system directory)\system32\drivers\etc\hosts" and add these lines:

127.0.0.1 avatar.heroes.nexon.com # Vindictus Korean Avatar Server
127.0.0.1 gamelog.nexon.com # Vindictus Log Server
127.0.0.1 avatar.vindictus.nexon.net # Vindictus US Avatar Server

i take no credit for this i am simply making sure people know about this
and i don't think you have anything to lose by doing this!