Is there any way to replace sql server file_guid with new GUID?
We had to do the same - as we wanted to copy a database to a new database, changing the name and file IDs at the same time.

We found the original process posted here to not to be repeatable, I guess it depends on how the original file ids were created.  In any event, I have updated the following procedure, which is repeatable.


Backup database from RDS to S3 using standard RDS database backup.

exec msdb.dbo.rds_backup_database
@source_db_name = '&lt;database-name&gt;',
@s3_arn_to_backup_to = 'arn:aws:s3:::&lt;bucket-name&gt;/&lt;backup-filename&gt;'

Restore .bak file into SQL Server on a local machine.  We have MSDN account, so we just downloaded SQL 2016 and installed, giving us full access to SQL on a local machine.  But, I believe you can download SQL Express and do the same, some functionality may be lost depending on the source version of the SQL Engine.
Perform a Export Data Tier Application for the database.  This will create a .bacpac file which includes the schema, data and code (stored procedures, etc.).
Delete the original data imported into SQL Server in step 3.
Perform an Import Data Tier Application and point to the .bacpac file created in step 3.  This step will set the file guids = _Data and _Logs, making them unique.
Do a full backup to get a new .bak file.
Upload new .bak file to S3 and do standard RDS database import.

exec msdb.dbo.rds_restore_database
@restore_db_name = '&lt;database-name&gt;',
@s3_arn_to_restore_from = 'arn:aws:s3:::&lt;bucket-name&gt;/&lt;backup-filename&gt;'