Removing a Rendering Extension
To remove a Reporting Services rendering extension, simply remove the Extension element for your rendering extension from the rsreportserver.config file, located in %ProgramFiles%\Microsoft SQL Server\MSRS10_50.<Instance Name>\Reporting Services\ReportServer folder. If you made entries for a Report Designer as well as a report server, remove the Extension element from the RSReportDesigner Configuration File as well. After the configuration information is removed, the rendering extension is no longer available to the component.
See Also
Concepts
Configuration Files (Reporting Services)
Implementing a Rendering Extension
Implementing the IRenderingExtension Interface