Tailgate locked shut. Need to get trim panel off. How?

[tdi_uk]

Hi everyone. The tailgate on my 2003 estate is locked shut. I'd unlocked the car using the central locking (fob) and had just pulled up on the tailgate handle when the lock seemed to relock but on the first latch, so half open. The central locking went dead leaving the rest of the doors unlocked and I could only use the key to relock the car. The interior lights, fuel flap, puddle lights also stopped working. After initially suspecting the CCM and it's wiring (clean, intact and dry) I found that fuse 14 covers all these systems and that it had blown. Replacing that restored everything back to normal except for the tailgate lock. I've managed to fully close the tailgate now but clicking the central locking on and off reveals no sounds at all from the tailgate so it would appear that something has shorted out in there causing the fuse to blow.

My dilemma is that I need to get the tailgate trim panel off to have a look-see. Unfortunately, the key has never turned the lock in the tailgate whilst I've had the car (since 2007) nor has the tailgate release switch worked in the drivers door panel or the middle button on the fob so I'm a bit booggered. I have no idea where the retaining screws are located, I can't even find any in the panel's handle recesses (are there any there?). Am I going to have to cut open the trim panel to access the lock or does someone know how to get it off? Or does anyone know why the key won't turn the lock to manually open it (key goes in ok and the barrel is free but it won't turn) and how to fix it?

Any help will be gratefully received.