Step 1:
The backside of this paper has a wood-pattern printed on. Prefold over this line.

Step 6:
Make a mountain-fold over the line at the left and a valley-fold over the line at the right. The piece between the 2 lines is half the width of the black piece at the left. Turn the model.

Step 5:
Pull the upper paper layer upwards. Then, make a valley-fold over the paper layer below (the wooden colored piece). Finally, push the upper paper layer downwards again.

Step 2:
Make a valley-fold over this line.

Step 4:
Make a valley-fold over this line.

Step 3:
The black piece and the wooden piece both have the same width. Make a valley-fold over this line.

Step 10:
Prefold over these 2 lines.

Step 8:
Push the piece indicated by the arrow flat from above.

Step 9:
Repeat step 7 and 8 over this red line.

Step 7:
Make a valley-fold over the red line. The corner indicated by the arrow is pulled upwards when you make this fold.

Step 16:
Make a mountain-fold over these 2 lines. 

Step 15:
Repeat step 13 and 14 on the other side of the hammer, see arrow.

Step 12:
Make a valley-fold over these 2 lines.

Step 11:
Pull the large flap indicated by the arrow upwards by making a valley-fold over this red line.

Step 14:
Push the piece indicated by this arrow inwards, below the flap in front of it. (the folding line is prefolded in step 10 too)

Step 13:
These 2 lines are already prefolded in step 10. First, push the piece indicated by the upper arrow downwards by making a mountain-fold over the upper line. Then push the piece indicated by the arrow below inwards by making a mountain-fold over the longer line below.

Step 17:
And make a mountain-fold over this line.