Make Content Wider on Twentyeleven Child Theme

My website uses a twentyeleven child theme. I use the 2 column format with right-side sidebar. I’m trying to widen the content area of my pages and posts (basically the entire site). I made a child theme and right now the only thing in the style sheet for my child theme is this:

/*
Theme Name: MyTwentyEleven
Theme URI: https://www.bestconcealedcarrygun101.com
Description: The new child theme
Author: Dustin
Template: twentyeleven
*/

@import url(‘../twentyeleven/style.css’);

I have seen some posts in the forum where people are saying to find this section and manipulate some of the values:

/* =Structure
———————————————– */

body {
padding: 0 2em;
}
#page {
margin: 2em auto;
max-width: 1000px;
}
#branding hgroup {
margin: 0 7.6%;
}
#access div {
margin: 0 7.6%;
}
#primary {
float: left;
margin: 0 -26.4% 0 0;
width: 100%;
}
#content {
margin: 0 34% 0 7.6%;
width: 58.4%;
}
#secondary {
float: right;
margin-right: 7.6%;
width: 18.8%;
}

Do I need to go to my parent twentyeleven them, copy this code from the stylesheet, and then paste this structure code into my child theme style sheet under @import url(‘../twentyeleven/style.css’);

And if so, what do I do to increase the width of the content area. Also, is it possible for me to keep the sidebar width the same. I just need a wider content area and less outside grey margin area.