Most of the Microsoft Exchange technical notes do a great job of explaining how to move a recipient's mailbox from one database to another. But there is little to be found about moving the recipient resources to different database. The short answer is that it is the same process.
So you don't have to go looking for the details, here are the steps to follow.
1. Get the Identity of the resource that you want to move. This can be found in the Exchange Control Panel or ECP under the Recipients / Resources. It will be the part of the e-mail address to the left of the @ symbol. In this example I will assume the resource is named as follows: ConferenceRm1@mydomain.com
2. Open the Exchange Management Shell on your Exchange 2013 server.
3. Use the New-MoveRequest command to create the migration process as follows assuming that my database that I want to move the resource to is MailboxDB04.
New-MoveRequest -Identity "ConferenceRm1" -TargetDatabase "MailboxDB04"
4. After executing the command you can view the status using the following command.
Get-MoveRequestStatistics -Identity "ConferenceRm1" | Format-List Status
The rest is just waiting for Exchange to process the move. Depending on the size of the resource it may take a couple of minutes to several hours.
We hope that this information is helpful. Please let us know how this has helped you or if you have additional questions. As always Firestone Technical Resources, Inc. is here to help with your computer support issues - "Providing personal service for your impersonal technology."