There IS threads about this.
any way... There's different ways to do this.
One is just to take the little screw in the top cap and screw it into the starnut. Then take a hammer and swagger on the top of the screw into the fork. Easiest way is if you have an inverted compression bolt, then just screw the starnut down to the fork from the bottom.
i think he meant to file down the edges of the flanges on the starnut so that it is easier to slide it in. but if you dont really know what you are doing, then take is to your local bike shop. they may install it for free
well then do what johan said. it works pretty good. thats how i did mine when i had ics. now that i have scs, i just had my local bikeshop do it for free.