You could buy your threadless fork from Inward. They wil install the starnut for you. You van also look at http://www.inward-scooters.com/Frequent_Questions.php. There is a description on how to make your own tool to do this right.
^ I don't understand how your name is MarkM when my old sr name used to be markm, But on a more serious note just hammer it in nice and steady with a socket or something around it or take it to a bike shop.