You can upgrade Backup Server at any point after you upgrade Adaptive Server using similar steps. XP Server does not have a formal upgrade process.
- If you are upgrading during the initial
server installation, select:- 
                        Upgrade Existing Servers when the installer prompts
                        Build
-  Upgrade Adaptive Server and Backup Servers
  This launches the sqlupgrade utility. Click
OK. 
- If you are upgrading after the initial installation,
start the sqlupgrade utility from the command
line. Enter: 
                    $SYBASE/$SYBASE_ASE/bin/sqlupgrade 
 
- Perform the upgrade steps as prompted.