It is a threaded fork I need a new stem so when i go to take the old stem out I took out the big long bolt and the thing that goes on the end of the bolt the expander thing its inside the fork its stuck how do i get it out the stem is a Syncros Cattleprod
If the crown is hollow or has a hole, you can poke something into the steerer tube from beneath to knock loose the expander wedge. Or put the steerer on a block of wood (so you don't mess up the threads) and lightly tap on the underside of the crown with a hammer...it might just fall right out. You could also take a wire coat hanger or something and bend a small, sharp hook onto it....fish it down the tube and see if you can grab onto the wedge, enough to loosen it.
If it's really setting up camp in the tube, you could leave it in there and get a new wedge, but eventually it'll rattle loose and drive you nuts as you ride. As a last resort, you could *gently* heat the tube with a small torch flame and that might loosen things up.