Looking for info: Andrew Guyan-28th Infantry Division (in Battle of the Bulge)

Hello. I am looking for anyone who could help me find information on my greatgrandfather. His name was Andrew Guyan (from Cambria Co). He fought in the 28th infantry division. I know he fought in the Battle of the Bulge. I don't know much else about his military history and thats where I need help. Id love to know his regiment or anything else. If anyone know anything or could help me Id love to hear from you.
Chris