The sidebar needs to be moved.

Hello, could you please help me? In the Zen theme, I need to swap the left sidebar and the content. As I understand it, this should be done in the css\layouts folder where there are four files, two of which are marked rtl. Which one should I change, or do I need to change all of them? I will have two fixed sidebars; maybe there's a simpler way to write the code since there’s a lot written there, apparently because the sidebar may not be displayed. Thank you in advance.