WordPress.org

This plugin is installed just like any other WordPress plugin. More detailed installation instructions are available on the WordPress Codex.

1. Download Blog Summary
2. Extract the /blog-summary/ folder from the archive
3. Upload this folder to ../wp-contents/plugins/
4. Activate the plugin in Dashboard > Plugins
5. Use the shortcode [blog-summary] on any page/post
6. Enjoy. And then consider donating

In other words, just upload the /blog-summary/ folder and its contents to your plugins folder.