Yes, in the end we opted for press-fit + glue as opposed to screws or interlocks for a variety of reasons and I must admit that we did not think anyone would ever want to open the case. Now of course this makes it more difficult for the few people like you who do want to open it. We have not yet tried to crack opened the factory units, since virtually all the units we have produced so far are being sent to kickstarter backers. But with the glued parts, it is clear that some damage will occur to the case if you try to open it.
As you saw in the STL file, 4 pegs protrude from the bottom half into the top half. I would just cut those with a hacksaw or cutting pliers or a dremel with the little saw wheel tool. A repair kit will soon be available for $12.99 including case, camera module, and fan - for the adventurous who really want to crack this baby open. Just make sure you do not damage the circuit boards inside.