This plugin modifies your .htaccess file to redirect requests to new locations. This is especially useful (and intended) to redirect requests to web locations/pages outside of your WordPress installation to pages now in WordPress. For instance, you could redirect
http://example.com/old/raw/web/user/enethrie/my... to
http://example.com/enethrie/ or
http://somewhereelse.com/
To install this plugin just copy the .php file to your wp-content/plugins folder, or use WordPress Dashboard to install this plugin by searching for it.