What you will want to do is to narrow the sidebar (#secondary) first and get that down about where you think you want it. You will have to redo some of your images in the sidebar. Then you will have to play with the right margin (decreasing the 38.0208% value) on #content and with the max-width, working those two together.
#content {
margin-right: 38.0208%;
max-width: 560px;
}
#secondary {
width: 29.5833%;
}
The border around the content:
#page {
border: none;
}
Image borders (including the header image):
#masthead img, #featured-content img, #recent-content img, .entry-content img, .entry-thumb img, .comment-content img, .widget img {
border: none;
}