It is very helpful to contact CX ahead of time in the US and indicate the changes you want. CX can see your ticket image if it is on AA stock (and it should be if issued by AA in CAI), all they need is your ticket number. Another option is when you fly US-HKG during check-in ask CX to fax HKG your changes and ticket info and prepare for a re-issue. They will research it while you sleep and be ready to re-issue, having settled all the questions. I've done this several times, and CX is very efficient at this if you give them a little advance notice. Then the reissue at the airport in HKG goes very quickly, typically 15 minutes (instead of the 3 hours that it usually takes with AA). Note that CX is very good at this (and will catch any rule infringements, so if you have a rules problem better use BA who never get the rules right, but will charge you an extra fee). For compliant tickets I have concluded that CX is the best (and I have had re-issues done by AA, BA, QF and CX). AA is also good but sabre just can't handle any aspect of these kind of tickets, so it winds up being a big challenge for the agent (for example the tax calculation software typically can't handle this many taxes on a single ticket; somehow CX can, and they have been 100% accurate in the tax calculation).