The spring is kind of conically shaped and is not down in the threaded shaft portion. It's up at the top.
You should be able to take your leaf button apart. There's a tiny c-clip (or 'e-clip) at the bottom of the plunger. Push the button down, removed the c-clip and the plunger portion will come out, revealing the spring.
I'll see if I have some pics somewhere.
Hope you're doing well MikeD'! 
Ahh very cool, that leaves me an option to play with.
Here's a pic of the tron button depressed:

I'm not planning on hacking up this button, but I don't own any other leaf buttons to play with at the moment. No clips, and it is quite resistant to being pushed back out. More resistant than I would have imagined. Thanks for the info, Mr. qb, and I hope you're doing well, too!

@Kremmit: Great lead as well! Thanks... this sucker is thin!
http://www.himuragames.com/images/buttons_scr_san_30_03.jpgThe leaf button still looks like it could make for the easiest hacking, and I could probably mount the leaf switch in a custom bracket and it would probably feel perfectly fine.
Thanks again everyone, glad to see I have a couple options
