Detach the silicon part first, then the top layer is snapped into the back layer, so remove the top gently, followed by the back piece to open up the case, insert ipad in the same way.
You can find instructions to install Survivor for iPad Air and iPad Air 2 here: http://grff.in/gv9on
If you're still having trouble after watching that video, please feel free to contact our support team. You can reach them here: http://grff.in/support