Sorry - I didn't understand the question in your earlier post!
You don't have to disassemble the headset - just unscrew and remove the star-cap at the top (screws into the star-bolt), remove the stem, then pop the Swing's top bracket over the steerer. If you've left a bit of steerer and some spacers above the headset, then you can choose to install the Swing bracket at any height among those spacers. Then re-install stem, (sequence is important here) fit and tighten the star-cap, then tighten the stem bolts. Job done.
PS - I also have a Chris King headset - lovely thing!