no real way to put that into words... just go slowly and carefully and wiggle this way and that until it slides out. which it does. the danger spot is right where the big bottom part joins to the little vertical channel piece. just watch that area carefully.
you are likely looking for a better answer like, go up then down then sideways but I sure don't have that one. just work with the knowledge that they do come out in one piece, you just have to figure out the puzzle moves..