The replacement link are assemby units and you do not have to do anything with the bushings. Some aftermarket products ( like Moog) are suppied with grease fitting, so you can grease them as a regular maintenance. Take a look on the following link:
http://www.rockauto.com/catalog/raframecatalog.php, just follow for your Windstar 2003 and go to suspension parts then "stabilizer bar link" for picture.