1. Close all instances of MR and back up the Management Reporter database.
2. Start the Configuration Console and click on the integration under ERP Integrations.
3. Click the Disable Integration button and wait a moment for that to take effect.
4. Click the Remove link in the top-right to remove the integration.
5. Stop the MR services at the top level of the Configuration Console.
6. Delete the ManagementReporterDM database from SQL. In prior versions, this database was called the DDM database.
7. In the Configuration Console, start the MR services and then click File -> Configure and deploy a new Data Mart integration.
8. Return to ERP Integrations, select the integration you created, and press "Enable Integration". The initial integration takes 5 to 10 minutes, but I've had it take up to a few hours.
Once the initial integration finishes, the data mart rebuild is complete.