How to remove the left sidebar ?

Is this any help?

https://www.ads-software.com/support/topic/remove-the-left-sidebar-from-twenty-fourteen-theme?replies=9

And how can I possible control the WIDTH OF THE PRIMARY SIDEBAR ?

No, this post was not as useful, since it’s just showing how you can create a new page template. But I want to use a 2 COLUMN LAYOUT that works for both, PAGES + POSTS !

So what I would need to figure out:
HOW CAN I CONTROL THE PRIMARY SIDEBAR WIDTH ?

Can you post a link to your site.