The headlight module doesn't release easily and has to be gently jiggled. The top of the assembly comes away much more easily than the bottom. It helps to try to lift the assembly vertically a bit by easing fingers under the bottom of the headlamp to lift the lugs from the slots. Continued jiggling, and easing of the top left bodywork eventually releases the headlamp assembly. Just keep at it gently until it comes away. If you're not going to remove it from the car you need to support it somehow. I used the top of some short aluminium steps.
There's some space to change the bulb at this stage but it's an easy matter to remove the headlight assembly completely from the car by uncoupling the electrical connector. There's a ridged locking tab which when pressed down allows the connector to be removed.
This shows the whole assembly sitting upside down. The headlamp bulb is removed by
unlocking the large circular access cover - turn anticlockwise to unlock.