OK, here's the pictures of where those pieces go, in case anyone else is confused in the future. I believe the top and bottom pieces on the elongated shin part will be removed, so you couldn't see where it was attached once assembled. I don't think you would have the right mobility, if those pieces stayed, and it would probably look funny.
And the other piece is mostly covered by the armor, it goes in the back piece, with some velcro going in the indentation that's showing, so the chest and back piece are connected, pretty different than the TK I am used to.
Thanks to the thechosenhitman for clearing that up for me, it will allow me to get a lot more done today, without fear I am screwing something up.