if you look on my coolerbator v3.0 there are a few pics of how I did it. I found that in order to be secure and adjustable without opening the bator you will have to have the adjuster sticking through the bator. from there be sure it can not slip of be bumped to a separate setting.
sorry I dont have any pics on the computer I am using, I had to carve out a section of the foam in order to make room for my lock nut. I also suggest a washer on the thread side, as the thermostat can pull through the flimsy styrofoam.