One thing I mentioned in my review is that the battery door on the BlackBerry Z30 is particularly snug. Kevin's finally got his mitts on one, and he bumped into the same problem of popping the door off. As simple as the problem might be, we want to make sure we're helping out every new Z30 owner as much as possible.
The only real starting point for opening the rear of the BlackBerry Z30 is the opening at the bottom. The instinct is to pry like crazy from there, but I haven't had great results that way. Instead, slide your nail to the left or right once in that opening; it should wedge between the silver frame and the glass fiber weave door. Keep running your nail through that groove, and the battery door should open up easily. I find it's easier going to the right side towards the volume keys, but going to the left will pop up the SIM and SD card cover soon enough, which give you something to work with.
Yeah, it's a simple problem, but spending five minutes wrestling with a new phone just to get the SIM in can easily sour someone's experience with their new phone - let's try and help 'em out, eh?