How do you fix third brake light on 2006 Bentley Continental GT?

The 3rd brake light is set in under the rear glass. Bentley has a superseded lamp assembly that can be installed without removing the rear window. It is a kit, and requires cutting the old one out and gluing the new one to the glass. We have replaced a few here, although not too difficult, you will have to remove the interior headliner to gain access to the connectors. The 3rd brake light is all led and is not serviceable.