3 Column Layout: Move Primary Sidebar to Right Side & Secondary to Left

There are three layouts for using both sidebars “3 Column Middle” “3 Column Left” and “3 Column Right”.
In “3 Column Middle” layout, Primary sidebar is in the left and Secondary (Smaller One) is in the right of the content section.

Please, help me shuffle the two sidebars. I want primary to the right side and secondary to the left.

How (code) and where (in theme files) I can achieve this layout?