not sure what kind of editor you mean. If it's the one for editing Board Information, just click on "Edit Board Info" in the Page Tools box.
As to html-editors, there are myriads of them out there, free ones and also lots of them to buy. Find free ones for instance here: http://www.techsupportalert.com/best-free-html-editor.htm
Or ask Google or similar searchengines, like in http://www.google.at/search?q=best+webeditor