OK Chirren... I got the switch apart on the #19e, and it wasn't too difficult in the long run (though I tried many techniques that have worked for me getting frozen-together Motorcycle parts apart - no joy). I almost used the old-cut-a-slot-in-the-magnet trick, but I wanted to keep the bottom magnet intact (I kind of like it now), and I didn't want to mar the brass button of at all possible.
What finally worked was placing the button on top of my padded vice (any sturdy flat surface with a bit of thin padding will work), pushed the button down so the magnet/cup was above the surface of the Delrin cup, and gave it a couple of good bashes with a nylon-faced hammer (you could also use a piece of plastic/wood/etc and a regular small hammer). Then I just grabbed a pair of my gripper disks (those rubber disks used to help open jars - my new favorite tool for getting stuck MODs apart), put them on either end of the switch and placed it in the heels of the palms of my hands & twisted in opposite directions - came apart as clean as can be.
There was absolutely NO glue on the button or post (at least in mine), but brass has a habit of "gripping" to itself much better than most other metals (galling). The force of the blows seemed to have been enough to break their bond so they could be twisted apart...whatever, the switch is fully dissasembled now without any damage or marks whatsoever ...
Let the modding begin!
Good luck
EDIT: On closer inspection, there was a very small amount of something in the threads of the fire button, but I don't know if it was really glue, or just general crud from the manufacturing process....since there was such a small amount, I doubt it was actually glue.....and remember - the button & post are functionally part of the switch, so they need to have good conductivity between themselves.