Your best (only?) option is the website self-service. Calling into AY agents at the time, I was told they could not change my flight at all since it's an AA ticket, and that any options online would be more than what they could offer. Perhaps this is more of a limitation in knowledge on the agents' part as it's hard to believe there are different policies for self-service vs agent involuntary schedule changes, but it still ended up being website-change only.

Other airlines that I saw pop up in the self-service for various routes included AS and JL (rare), which might be helpful for your Asia itinerary.