Amazon Relational Database Service
User Guide (API Version 2014-10-31)

Resetting the db_owner Role Password

If you lock yourself out of the db_owner role on your Microsoft SQL Server database, you can reset the db_owner role password by modifying the DB instance master password. By changing the DB instance master password, you can regain access to the DB instance, access databases using the modified password for the db_owner, and restore privileges for the db_owner role that may have been accidentally revoked. You can change the DB instance password by using the Amazon RDS console, the AWS CLI command modify-db-instance, or by using the ModifyDBInstance action. For more information about modifying a SQL Server DB instance, see Modifying a DB Instance Running the Microsoft SQL Server Database Engine.