you might try .rptInspector, from what I have seen it is pretty useful.
Depending on what changes in the migration would vary what you need to do.
If the table names change or the column names, you would need to change that. If those don't change, you might be able to get away with just changing the connection...if you use ODBC, you would need to tell CR which type of connection you are using....
It's been a really long time since I needed to do this, but what you will need to do is change the driver file for the connection.
Unfortunately (or fortunate for me) I never encounter this as my company passes XML datasets to the reports...so they don't know/care about the datasource.
HTH