Perhaps I'm unclear on the concept

My thermostat was flashing "LO BAT" at me, and while I thought for a moment that it was flashing "Lobot", it was pretty obvious that the thermostat was actually saying that its battery was low. I hadn't realized that it was battery powered, but that's ok--I'm assuming that the guy who installed it told me and I just forgot.

The problem was that there was no obvious way to open the case to get at the batteries. No catch, no latch, nothing. Laugh, because it's funny, but I was raised in a house where a thermostat was not exactly a necessity. Or even a presence.

I looked up the instructions online. They showed the unit with the cover off for installation, and instructed the user to "replace the cover", but no "press here to open". I was a little wary of just trying to pull the thing apart, because I could imagine the unit coming off the wall. When I finally gave up and went right up to the thing, I could see the following message in raised letters on the cover: "Battery powered - instructions inside cover."

Um.

So I just pulled, and I must have done something right because the cover popped off into my hand. Sure enough, there were instructions for opening the case and replacing the batteries...on the inside of the cover. Specific instructions, too, on the order of "these switches must be in this position in order to open the case."

Maybe I'm missing something, but it seems to me that that's not the ideal spot for that information.