This topic contains advice for dealing with some common problems that can arise when deleting resources:
If the deployment step fails because you have already deleted the broker by using the mqsideletebroker command, or the broker is otherwise unable to respond, remove the broker from the topology in the workbench. Ensure that the broker's SYSTEM.BROKER.ADMIN.QUEUE queue has been deleted, then start another topology deploy.
The broker should now have disappeared from the workbench.
Do not try to re-create a broker by using the mqsicreatebroker command until you are confident that it has been removed from the workbench. Similarly, do not reuse broker or queue manager names until you are confident that they are not in use elsewhere.