Use the restoreConfig command to restore the configuration of your node after backing up the configuration using the backupConfig command.By default, all servers on the node stop before the configuration restores so that a node synchronization does not occur during the restoration. If the configuration directory already exists, it is renamed before the restoration occurs. If you directly make changes to the application files in the app_server_root/installedApps directory, a process known as "hot deployment", but do not make the same changes to the application files in the app_server_root/config directory, the changes might be overwritten if you use the restoreConfig command.
I tried restoring the configuration from WAS_DM_08_28_2009.zip file on my DMGR it took couple of minutes to execute this command
Now if i look at my DMGR_PROFILE directory i can see that the config directory before i executed restoreConfig command was renamed to config.old and the content of WAS_DM_08_28_2009.zip file was expanded into config directory