Avant upper tailgate light

I haven't attempted this yet (and I don't think it will be a major job given how much i've modded this car) but before I start... Does anyone know how to access the top light on the outside of an avant tailgate? And what bulbs are inside?
Mine seems to be a bit dead on one side. I always thought it was an LED strip but apparently not. My MOT/Katsastus guy told me last year it needs to be fixed. So I've now remembered 11 months later to fix it. Could be worse. Could've been 12 months :)

I've searched the forum but haven't found anything. If nobody knows about this I'll work it out and post my findings here.
excellent. thanks. I hadn't even noticed those little end caps. I need to take a close look tonight when I get home. Maybe I need to replace the whole ****** unit rather than bulbs? bugg3r.