You can't modify the head in Pro. It was most likely modeled in another package (Alias, 3D Studio Max...) and brought in as an IGES file and you can't modify an imported IGES file
I GUESS THE QUESTION I HAVE IS CAN I CHANGE THE POSITIONS OF THE ARMS, LEGS, STANDING, SITTING. THERE IS A SECOND SHEET WITH THE NAME .LAY. IT SEEMS THAT YOU COULD MODIFY THIS AND CHANGE THE BODY FROM THE GENERIC STAND STRAIGHT VERSION. NOTHING MEANT BY THE CAPITOL LETTERS.