Move the Sidebar to the Left/Right or Remove it

1. Go to Theme -> Edit HTML -> click anywhere on the code once (necessary) -> press CTRL+F (or CMD+F on Mac) and paste this in the small search box that appears: <body class='2. And change the class to no-sidebar, left-sidebar or right-sidebar.

It should look like this: <body class='no-sidebar'><body class='left-sidebar'><body class='right-sidebar'>3. And click on "Save theme".