To get Bing, you do not really require to do much. This is because you are not going to download or install anything. You simply need to type "bing.com" into your browser and it will come up like any other website, after which you can bookmark it. Visit http://www.ehow.com/how_5065686_bing-search-use.html, for more details.
i think you're trying to change your homepage. to do it for you firefox, go to the options page for the browser and you'll find a "homepage" tab , and type in there whatever site you want to be your homepage.