my flights are:MAN-MCOPHL-MAN
I called and they let me add it for a $50 change fee.I was about to purchase a separate flight, but now i got an almost free one in first class. :-)
if its on CO hopefully you chose a flight where CO is using the 752 instead of the 737, as Biz is BF OK its a short flight but the 752 is 1000% better seat wise and it has AVOD