i ordered a sp2 initially, it came with instructions for button dis-assembly. thermo didnt for some reason, probably cause i ordered it weird.
pretty simple, take off the atty, the atty connector cap, and remove the batteries. i have penstyle attys, but i imagine this will work with any atty as long as the mouthpeice tip is firm.
you should have a tube, with the button connector still attached. take the atty, with mouthpeice attached, but Not the connector cap. set it upright on on a flat surface, so that the threads are down and mouthpeice is up.
take the tube with the button attached, line up the bottom button with the top of the cart thats attached to the atty.
give it a medium tap, not hard enough to damage it, but hard enough to get the job done. you should feel it coming apart.
now you can unscrew the button cap.
should have the button cap with threads, a spring, the white washer, and the button itself. give em a cleaning. personally, i used some oil that i oil my handgun with, not sure if thats safe or not. but i imagine any lubricant will work.
i oiled the button peice and the round part of the housing that the button slides in.
now put the button in the housing, slide the spring back on the rod part of the button and put the washer thing back on. press together so they fit nice again, and now you should have a nice clean easy to press button.
whew, hope that all made sense (very tired at the moment). might sound complicated, but its very easy once you do it your first time. if you keep your thermo in your pocket like i do, sometimes gunk will accumulate on the site of the button between the housing and button itself.