To remove a Reporting Services delivery extension, simply remove the Extension element for your delivery extension from the configuration file. After the configuration information is removed, the delivery extension is no longer available to the report server.
Once a delivery extension's corresponding Extension element is removed from the configuration file, it is no longer registered with the report server. The report server removes the entry from the list of delivery extensions and deactivates any subscriptions which use that delivery extension. When a delivery extension is removed, users are no longer able to select it as a method of notification.