I'm in a similar boat with award tix I booked 5 days ago for goalie-parents & goalie-aunt where I grabbed what I could as it was 3 saver business int'l tix and am looking for better dates and with that, my take on changing an award ticket would be to see if (n.b. if) the website shows availability on the dates you want and if it does to call as frankly, I just don't trust and/or feel comfortable with the website and how it and the "new system" works. Also, even if you don't see any availability on-line, I would still call as when I saw the flights on-line, I called reservations to see if they could anything better and the agent couldn't even see the availability I could so perhaps the reverse where the agent can see something and you cna't might be true.