Well. It may LOOK like one piece but it is not. Use a crescent wrench or large channel locks to hold the hex and twist head counter clockwise (looking at the head from the bottom). It will come right off. It looks seamless but it's not. And very often I am smarter than everyone else around me.
I don't know what the crying is about. Page 14 perfectly describes what is required to remove the head from the 128cd. Simply take a pair of channel locks and grab the hexagonal fitting above the head and then twist the head counter clockwise. Comes right off