Need to remove interior light unit (need help!)

I changed the standard bulb once before so I did it agian as usual, but in the process of putting the new bulb in I lost the the bulb connection in the unit as shown in the picture below now I can't access the connection to put the new bulb in and I also don't know whether the wiring is still all together so can anybody give me some advice and/or tell me how to remove the whole unit, I am also from te uk
Many thanks