[Dmitry at Pelican Parts]

Hello Bedlam and welcome to the forum! It sounds like a replacement is needed. I'm attaching a link to one of our site's DIY tech articles on this procedure. Please let us know if you have any questions or if we can assist with any future part needs.

https://www.pelicanparts.com/techarticles/MINI_R56/37-ELEC-Third_Brake_and_License_Plate_Lights_Replacing/37-ELEC-Third_Brake_and_License_Plate_Lights_Replacing.htm