Not sure it was the best, but this is what I did last year. I was in Beijing when an injury required an early return. I purchased a prepaid international calling card and called the EXP number in the USA (was EXP last year). The tickets were a combination of an award and a purchased with VIP upgrade. The changes required rerouting from China in addition to an earlier date.

The changes were handled efficiently and I had time left on the card, which I gave away. I don't remember the cost of the card, but it was not too much.

I used an alternate approach on 9/11 when I was stuck in Equador. I emailed a friend in the USA and gave him my FF number and the EXP phone number. He arranged the best options for me and emailed them to me.