I cannot vouch specifically for the Jetbeam, but it looks like my Ultrafire wf-1200. I replaced the switch in mine to a forward clickie, so I'll give it a stab.
The red center does not screw out, it is a spacer for the switch and board. USUALLY, there are two small holes in the silver ring and this is what screws out. Maybe they put it in backward to prevent people like us from screwing with it. Maybe try this, but very carefully: Try drilling two small holes, not all the way through, the outer silver ring 180 degrees from each other. Be careful and don't drill too big or deep. Then you should be able to unscrew it with a pair of small needle-nosed pliers. Once the silver ring falls out, the inner red will too, as should the switch soldered to the board.
Next, find a forward clickie switch that have terminals long enough to reach the old solder points on the board. The forward clickies are taller (at least the one I used) and a taller boot will be required. Solder the new switch onto the old board and reassemble. I got a switch for a DBS from Flashcrazy at flashlightconnection.com (Thanks Jay!:twothumbs) and used a taller "tactical" boot from lighthound. 30 seconds to solder and done.
Sorry, I don't have a photo site account ot post pics, but I may be able to email you some photos, if you need more clarification. Disclaimer: this is how your switch looks to me, however please only try this if you are comfortable this is how your light is set up.
