If you have the HPSIM 7.2 DB backup or you have used DMT to back the HPSIM please follow below steps:
**** DB Backup for HP SIM 7.2 is available
1) Uninstall HPSIM 7.3
2) Install Fresh HPSIM 7.2
3) Reconfigure the HPSIM 7.2 DB to the backup (HPSIM 72 Backup DB).
4) install Updates
Manually re-registering a new database by altering the HPSIM configuration files
1. Create a backup of the database.props, database.admin, databaseadminupd.tpl and databaseupdate.tpl files located in <installation directory>\HP\Systems Insight Manager\config.
2. You must modify some settings for the new database changes in Systems Insight Manager in each of the following property files: database.props, database.admin, databaseadminupd.tpl and databaseupdate.tpl files. Update these files with the following information, and then save the files.
a. Change the value after hp.Database.hostName=source-server-name to target-server-name.
b. Change the value after hp.Database.instancename=source-server-name \\source-instanceto target-server-name\\target_database_instance.
c. If the database user account is a local user account, change the value after hp.Database.username=source-server-name to target-server-name\\username.
d. If moving to a different SQL server, it may use a different port. If this is the case, update the value after hp.Database.portNumber= to the new port number.
3. Create a backup of the hpsim-ds.xml file located in the <installation directory>\HP\Systems Insight Manager\jboss\server\hpsim\deploy directory. Do not place the backup file in this directory.
4. Modify the hpsim-ds.xml file located in the <installation directory>\HP\Systems Insight Manager\jboss\server\hpsim\deploy directory.
a. Locate the line with the <connection-url> XML tag; it will look similar the following: <connection-url>jdbc:jtds:sqlserver://dbServerName:1433/Insight_v50_0_###; loginTimeout=20;domain=dbServerName;instance=source-instance</connection-url>
b. Change the dbServerName text from the old SQL Server host name to match the new SQL Server host name.
c. If moving to a different SQL server it may use a different port. If this is the case update the port number that follows the first dbServerName (for example, dbServerName:1433).
d. If the target database has a different database instance, update the instance name after the instance= parameter.
5. Start the Systems Insight Manager service.
NOTE: The above steps are copied from “How to Move an HP Systems Insight Manager SQL 2008 Database from a Local to a Remote Server White Paper Systems Insight Manager Installation Directory” .