I have just gone through exactly the same process. What I found was: 1. change the RETURN DATE before changing the outbound date - that at least allowed me to select a new outbound date, to start with it had refused to allow me to select a date other than the few days before the return date 2. When it refuses to allow you to select a sensible timed flight (the spinning loading ball) (and if you have a FLEX ticket which I did), then select the crap flight and book it. THEN GO BACK and just change that flight, at which point it allowed me (after twice getting the spinning loading ball) to select the flight I wanted. I would also add that I had to log back into my account between every step - incredibly frustrating - and that I tried to book a new flight using Business Plus account and found it was more than 10 percent more expensive. SO I won't make that mistake again! Cathay's website is a heap of ..... Absolute .....