delete all extra toolbars - when click tools and add-ons don't know how to execute delete of 3 yahoo toolbars and retore google as defalult

Yahoo asked me to update firefox for better security and I made the mistake of clicking on the yahoo link. So when it updated it added at least 3 toolbars and wiped out google as my default. I followed the suggested visit to tools-addons to delete them but had no idea what to click on the page of symbols to get the delete action. And I've no idea how to restore my default to google. I'm a real April Fool.