Originally Posted by
alggag
The only way I know of is to go to Flight > Manage Reservations, then enter name and PNR. There should be a link for Add/Edit Passport information right under your name unless that's what you're already trying to do.
This works, thanks!
Through [My Account -> Upcoming Trips -> Change], non CP passengers was pretty quick and easy to do since it lists all members of the travel party in one spot. This alternative method is perhaps less efficient, but probably a little more intuitive and works for companions as well.