Yes thats done it. Thank you very much for your help.
Would have taken me a while to find and edit the current CSS.
Hi Bojan
Heres a screenshot of a typical page.
https://www.dropbox.com/s/1bt197ytm82fba7/Screen%20Shot%202015-07-27%20at%2016.03.51.png?dl=0
I have removed the sidebar widgets. Ideally I would like the post width to be the same as the navigation bar ( red arrow).
There are also embedded files which is at 100% width of the post. Hopefully If I can find a way to make the width wider, the embedded files will follow suite.
I would love to direct you to the blog post but the site is actually locked up behind Google Authentication.
The theme used is the WP knowledgebase theme. Heres an example post
http://ipanelthemes.com/kb/wp-knowledge-base-theme/kb-overview/wp-knowledge-base-theme/
The CSS is standard.