1) Take the little foam ring out(around the batt spring) and see if there is anything "underneath" the driver board to keep it from bending down when the button is pressed. If not, carefully bend the board to mid-point, and use foam or something to support the underside.
2) I found the switches cheap at Digi-Key. They are 6x3.5mm Tactile switches. Digikey item # 450-1140-HD. when u get them, carefully snip off the flat end of the terminals and solder them onto the driver
This of course is assuming you can get it open carefully without killing the tube, and carefully desolder the original switch.
I ordered 10 of em That way when they go bad(and they will since the laser draws more current than they are rated for) I can just change the switch. There is NO switch of this size to handle the current the laser draws.
Ok. that leaves the fun part.. getting the tip off the tube. There are two types of tubes from the DX lasers. One has "laser pointer" stamped into the pocket-clip, and an aluminum-looking button. This tube is thicker, and actually easier to open.
The other tube had a plain chrome clip, no writing, and a chrome-looking button.. This one is a real party(sarcasm intended) to open.
For the first type, clamp the "tube" tight about 15mm down from the tip(leather comes in handy to prevent damage), then clamp the tip carefully with vise-grips(again leather helps you not to destroy it) so you don't crush it, again tight right at the end, and wiggle/pull until it comes out. The module will easily push out the tip-end, once unclamped. DON'T try to push it out past the button end.
For the second type, Clamp the tube in the same spot, very firmly to prevent the module twisting inside(death to the driver). Clamp the tip in the same manner, and unthread it. Unlike the first type, this tip is threaded onto the brass module inside. To reassemble this one, you have to thread it back together the same way. First insert the module so the button lines up, clamp the tube again to hold it, then thread the tip back in. SOMETIMES you can thread the tip on the module first, then line up and press the whole thing back in.
On either one, the tip is press-fit and VERY hard to remove.
Replacing the switch is a cinch, provided you have soldering skills.