Thanks for all your replies. I'll post how i go. Anyone willing to speculate on what happens to the fuel surcharges, if they reissue?
They are recalculated. I did a reissue recently where I got a refund of fuel surcharges and other taxes after a reroute - ended up paying only about USD40 for the reroute (so US$85 of taxes was in effect refunded).
In my case all the initial setup and the changes were arranged via the AA RTW desk. The initial issue was on paper from AA's GSA in MNL, and the reissue (as an e-ticket) via AA's GSA in HK (they needed to retrieve the paper tickets).