Okay, I was in serious WTF mode trying to get the battery out without destroying the Trackr Pixel. VERY FRUSTRATING! Poor design. How about putting something like a slight slot in the back where a penny or nickel would get enough grip to open it???
Okay, Here is how I got it open.
Duct Tape (Gorilla Tape in my case). Tear off a piece about the size as the Trackr Pixel, say .75" or so. The duct tape itself is the "normal" 2" kind.. So now you have a piece that roughly measures .75"x2". Stick it to the face of the Trackr Pixel so that the Trackr Pixel is covered and most of the tape is hanging off. Now make another one the same size as before and stick it to the other side of the Track Pixel but with the excess pointing the opposite of the first piece.
Now, simply pull, in a twisting motion, the two pieces in opposite directions making sure the piece of Duct Tape on the back is being pulled in the "open" direction and the Trackr Pixel will open.
No pressure (Squeezing) needed to open it.
Kinda looks like this with the tape on it: