Now lay the front head and body down, right side up, and position the ears. Then lay the head and upper back piece on top. Place the back bottom on top of the ensemble, lining the bottom edge with the bottom edge of the front piece. Basically the back will have an envelope opening for the heated pillow.
Pin everything into place, but remember to leave spaces for the limbs: essentially one at each corner.
Sew around the entire panda remembering to lock the stitches at either side of each of the limb openings.