WordPress.org

You can use git to fetch the symfony component libraries or you can also just download them by hand and copy them under the lib folders.

1. Upload wp-sf2.php to the /wp-content/plugins/ directory
2. Activate the plugin through the 'Plugins' menu in WordPress
3. Run the commands

cd wp-content/plugins/
git clone git://github.com/cordoval/wp-sf2.git
git submodule init
git submodule update