Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.1030 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
You can't have an open-jaw on an AAdvantage award. You have two separate awards: PER-SYD, and HKG-LAX.
If both awards are on a single PNR, just call AA and cancel the first award, or change it to a later date. You can cancel with no charge; you only have to pay if you want the AAdvantage miles associated with the first award to be reinstated to your account.