Step 1:
This is a complete white Origami paper.
Prefold in half over the four lines.

Step 2:
Valley-fold over the two lines at the bottom right, mountain-fold over the two diagonal lines. And valley-fold over the two lines at the top left.

Step 3:
Fold this flap straight upwards.

Step 4:
Squash-fold.

Step 5:
Valley-fold over both lines.

Step 6:
Unfold the folds of step 5

Step 7:
Fold this edge downwards.

Step 8:
Press these edges downwards / flat.

Step 9:
Fold the triangle flap upwards.

Step 10:
Open the model.

Step 11:
Fold the triangle flap to the inside

Step 12:
Close the model again

Step 13:
Repeat steps 4 to 12 on the other three large flaps, see arrows

Step 14:
Bookfold this edge to the left.
Then rotate the model, see next step.

Step 15:
Fold the corners indicated by the large arrows to the centerline (see small arrow).

Step 16:
Valley-fold over these two lines.

Step 17:
Bookfold the edge on the right to the left.

Step 18:
Repeat steps 15 to 17 on the right, see arrow.

Step 19:
Open the model on the left, see green arrow, and turn the model

Step 20:
Fold over this line.

Step 21:
Pull the tip of the flap downwards by making an inside reverse fold over the 3 brown lines (=mountain-fold over the line in the middle and a valley-fold over the 2 shorter outer lines).
Valley-fold over the green line while you do this.

Step 22:
First valley-fold over the line below.
Then mountain-fold over the line in the middle.
And mountain-fold over the upper line.

Step 23:
Bookfold this edge to the right

Step 24:
Repeat steps 20 to 23 on the left, see arrow

Step 25:
Valley-fold over this line.

Step 26:
Mountain-fold over this line

Step 27:
Mountain-fold over this line

Step 28:
Repeat steps 25 to 27 on the left, see arrow.

Step 29:
Valley-fold over the upper diagonal line and mountain-fold over the line below.
Make the same folds on the layer at the back, mirror-wise.

Step 30:
Make an outside reverse fold over these lines.
Make the same fold as the short line at the left on the layer at the back (=mountain-fold)

Step 31:
Press the upper part of the leg flat by making a mountain-fold over this line.

Step 32:
Press this part of the leg flat too.
Then push it to the left, see arrow, against the fingers which are holding the upper leg.

Step 33:
Valley-fold the tip to the front on the spot indicated by the arrow.

Step 34:
Repeat steps 29 to 33 on the other leg

Step 35:
Press the upper-arm flat by making a mountain-fold over this short line

Step 36:
Press this part of the arm flat too.
Then push it to the left, see arrow, against the fingers which are holding the upper-arm.

Step 37:
Repeat steps 35 and 36 on the other arm, see arrow

Step 38:
Mountain-fold over this line.

Step 39:
Press the 2 edges inwards by making an inside reverse fold over these two sets of 3 lines

Step 40:
Press the neck further inwards, see small arrows, keep holding the neck while you fold the head downwards over the two brown lines.

Step 41:
If necessary, press the neck further inwards by making a mountain-fold over the two brown lines

R E A D Y !
This is a video tutorial for folding the human skeleton: