They actualy are amost simpler then the threaded ones you used to work on. Main difference is on top you don't have a part that threads down on the fork.
Check out the barnett manual posted at the top of this forum. Depending on who makes your headset, some have complete breakdown diagram of their headset.
For example Chrisking - if you scroll down and download the PDF for their no threadset.
http://www.chrisking.com/tech/tech_PDF.html