To perform an in-place upgrade:
Patchadd the appropriate patch. For details, see: Patch and Package Information for Messaging Server
From the msg-svr-base directory, run patch-config. For example: /opt/SUNWmsgsr/sbin/patch-config
From the msg-svr-base directory, run install-newconfig. For example: /opt/SUNWmsgsr/sbin/install-newconfig
To back out the upgrade, run uninstall-newconfig from the msg-svr-base directory. For example, /opt/SUNWmsgsr/messaging/sbin/uninstall-newconfig
Be sure to patchrm the appropriate patch listed in Patch and Package Information for Messaging Server.