How to make Responsive Theme fixed-width.

I want to remove the “responsiveness” from the Responsive Theme. I have set the wrapper width to 960px. However, the “responsive” actions are still happening when you size the browser down.

I have created a child theme but only have limited knowledge of .css and .php. I have almost no knowledge of functions and .js. But I am good at figuring things out.

So could someone help me out?