After you open your website in Visual Studio, double click on the master page and you will be able to edit the HTML:http://screencast.com/t/tvp2cBbh4e
. If you do not have Visual Studio, you can open the master page with a text editor of your choice and edit the html.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items