I disassembled mine when the switch went out. I buggered it up pretty good though. I'll try to describe it. Underneath the top cap is a plug in the top of the tube. I used a screwdriver to slowly lever it out. From the top you can then see a ring in contact with the tube with the circuit board inside. This assembly has the circuit board, switch, LCD, and on off buttons. There is a plastic housing for the buttons. I used a drift on the + battery contact to push this assembly toward the top. BUT once you get it moving it has to be rotated to clear the frame around the LCD. IIRC you can see the flat spot on the assembly from the top side.
I'll look more when I get home this evening. I'm not sure posting pictures would help but I'll see.
Good luck!
BTW the switch did not appear to be standard to my eyes.