1) Under the “Site” menu, click “Design.”
2) Click “Design Options” icon in the bottom right of the browser (icon will be a painter’s palette).
3) While under “Theme” click on “Options.”
4) Click the drop-down menu next to “Design Width” to change the width.
5) Click “Save.”
6) You can preview what the width change will look like before saving.
7) To save changes, click “Save.” Clicking “Cancel” will remove the changes and the page will immediately reflect this change.