To enable Service Broker run:
ALTER DATABASE [Database_name] SET ENABLE_BROKER;
To disable Service Broker:
ALTER DATABASE [Database_name] SET DISABLE_BROKER;
To check if Service Broker is enabled on a SQL Server database:
SELECT is_broker_enabled FROM sys.databases WHERE name = 'Database_name';
If the result is ‘1’, the Service Broker is enabled.
Thanks to zarez.net for this useful article.