Switch to the Broker Application Development perspective.
In the Broker Development view, right-click the message category
file (*.category file extension) that you want
to delete, then click Delete on the pop-up menu. Alternatively
select the message category file in the Broker Development view and then either
click Edit> Delete, or press the Delete key on your
keyboard.
On the Confirm Resource Delete window, click Yes to
delete the message category file. Alternatively, to cancel the message category
file deletion, either click No or press the Esc key.
Tip: Once you have deleted a message
category file, the action cannot be undone.