Fault light from behind it doesn't work

Hello,

I have a Citröen Xsara 1.9 TD Image of 1999 and I have broken a bulb of the fault lights from behind. I have opened a lid that covers it inside the trunk ... but you see only a screw with a nut and, in addition, a power outlet.


Should I open that screw to get "all the optics"

how do you access the play of lights?

The bulb of that fault light, does it come in the lamp box that Citröen brings as standard?