When I first read this topic, I came to the conclusion that it was in reference to the title of a site, though it never really said that, so now I'm not so sure.
Are you trying to adjust the header text of elements, or rather the title of your site?
Adjust the text in the headers of your elements can be done by clicking on the edit icons on them, and then typing in the box that appears in it's header text area.
In the case of changing the sites header title at the top of the page, you'd follow the first instructions I gave, and look for the box that says "Default Website Title". What you put there will appear in the header area of your site at the top.
