try this...
use a long-ish bolt to thread into the star nut...the park tool is great, but if you don't have one and are doing it guerilla-style, use this longish bolt as you would the park tool. take a rubber mallet to the head of the bolt and bang 'er in. and yeah, I have found that if it goes in a little crooked you can center it with a screwdriver or even the bolt it self, just don't bang it in too far! you may want to give the star spanky a little "coaxing" in a vice to bend the flanges a bit more - it goes in easier. best option: get a HEADLOCK by Azonic...no more star spanky, easy assembly of headset, and added security. good luck
gabe