Ohodnoceno 4 z 5 hvězdiček

To remove the message header toolbar entirely, put the following line in userChrome.css:

#header-view-toolbox { display: none; }

Edited to add: to have the message header buttons display normally(to the right for LTR languages) use the following:

#expandedHeadersTopBox { display: block; }

Apparently this is overwritten in the extension, and it is what allows the From and buttons to be moved with CSS.