You can uninstall the plug-in via Add/Remove Programs from Control Panel or by using an application which handles software uninstallation. From that category you can use CCleaner's uninstaller which provides, beside actual uninstall features, registry cleaning operations.
Download and install the program, then go to Tools > Uninstall and remove the plug-in. In case it's a browser plug-in, please use the Add-ons/Extensions menu to remove it.
