Do you know the Blender software? When you open the file you are directly in the shading area.
There are two Genesis figures (FROM and TO) to see. The first, the sources of the images are set (Face_GF2, Torso_GF2 and Limbs_GF2).
The output images are then generated for the other Genesis figure, these would then be Legs_GF3, Face_GF3, Torso_GF3 and Arms_GF3.
If the figures in the upper window are no longer selected, you must first select the figure (From (the Sources)), then the other figure (To (the Output). Then you can press the "Bake" button. This can be found on the right side under "render properties" (a small symbol of a camera).
When the computer has created the images, you can save them individually (bottom left in the window).
If you don't get it right, let me know. Then I could create a PDF of it.