Upload the entire folder of the plugin ('sidebars' folder) to your plugins directory ('/wp-content/plugins/' folder).
Activate the plugin through the 'Plugins' menu in Wordpress.
A new item on the menu will appeared that says 'Sidebars'.
Also, in your template files, location the function dynamic_sidebar and replace it with go_sidebar. The dynamic_sidebar function could be anywhere but it will mostly likely be in the sidebar.php file.