For the benefit of others the integral to rear valance, Hella style fog and reversing lights are accessed from inside the rear panel after removing spare wheel. The inner part of lamp is on a bayonet so can be removed for bulb access by turning anti-clockwise about 30° as viewed from inside. There is a rubber seal which may benefit from a little vaseline on re-fitting although I've had no issues with water ingress.
Ref René's comment above, an upgrade to LED replacements will give much brighter rear lights or you can have double reverse or fog lights (loom wiring already present) as per
this thread although involving a lot more work.