All add-ons from Rikoooo must be uninstalled by the same way:

From your desktop, click "Start" then "All Programs" then find "Rikoooo Add-ons"and open it. Now appears a list of add-ons from Rikoooo installed on your system. Symply choose the one you want to uninstall.

From that same location, you can also access all the informations about your add-on: Manuals, copyrights, directory, readme files and so on...