Ah hah, I see what your first problem is.  You do not turn the figure into anything, leave it alone.
Load Alyson and go to the material room.  See the image_map with AlysonBodyNG?  It's that map that you want to load into Gimp.  This is how you do it:  Open Gimp, it should have a Browser.   Browse to C:/Users/Public/Public Documents/Poser 8 Contents/Runtime/textures/Poser 8/Alyson/Alyson-and there they be.  Select AlysonBodyNG and import it into Gimp.  Now as soon as that is done, save it under a new name so that you don't hose up the original.  We will stop there until you tell us if you are successful before proceeding.  Jan