Remove sidebar from Optimizer theme content area

Hi, I am using Optimizer theme on my website http://www.pushbikepa.com. I would like to remove the div.sidebar or div.widget? The white box at the top right part of my content please. It’s below the header. When I do ‘inspect elements’ in google, it says various things about this part of my page: div#sidebar.home_sidebar 286.422 px x 70 px OR div.widget_wrap 286.406 px x 40 px…Is there some CSS code I can put in my custom code setting that can get rid of this white box and not leave a ‘hole?’ Thanks in advance.