It's not possible to change the database server in the MSP configuration; you will need to uninstall and reinstall the MSP software. My suggestion is to do the following:

Backup your MSP objects using the XML Export function in the MSP web console. I also recommend to backup the Motorola MSP directory in the Program Files directory (or wherever you installed the MSP software) because it contains a repository of all your packages.
Stop all MSP services on the MSP server.
Export your MSP database using the SQL Server tools.
Import the MSP database on your new SQL server.
Perform a new installation of the MSP software on a separate test system (in other words, do not touch your existing MSP server), and point it to the MSP database on your new database server. This way, you can check if the MSP database was correctly transferred to the new database server while your old MSP is still intact.
If the test in step 5 was successful (i.e. all packages, settings, bundles, profiles, policies, relay servers, etc. from the 'old' system are also available from the new database), you can uninstall the MSP software on your production server and reinstall it to use the new database.