Fastest way- remove tailcap, drop out batteries.
Push switch, and pinch off the rubber cover.
Take a small allen-wrench (the size that JUST fits into the hole) and push it into the hole in the center of the switch. unscrew a few turns.
You MAY have to remove the head of the light, and push on the bulb-holder, but I can remove my with a shake. THe allen-wrench only needs a few turns- too many and you'll totally unscrew it. The switch assy should drop nicely out the tail-end of the tube.
In the D-cell lights, anyway, this works. You will NOT need to remove any retaining rings, or need special tools (other than the allen-wrench). I have both old and new versions of the D-Mags, and this works on both.
