Step 15- making the other eye.

Duplicate the layer (Ctrl+J) to make the other eye, and change the size (Ctrl+T)

Merge the layer with the first one. And continue with the free transform until you get the result you want.

Step 16 blendig the eyes

Reduce the saturation (Ctrl+U) or Image – Adjustments- Hue/Saturation. Saturation at: -53.

Step 17 – keep blending

Duplicate the eyes layer and use the layer in soft light mode with 30% of opacity.

Step 18- Finding the nose

Pick the nose from another skull, and select it with the lasso tool, press Ctrl+J to copy the selection.

Step 19- reduce the nose

Make the nose smaller with free transform (Ctrl+T).

Step 20- less saturation

Reduce the saturation of the nose (Ctrl+U) or Image- Adjustments- Hue/ Saturation. In the option Saturation: -70.

Step 21- more details

Fix the nose with the smudge tool.