Worsester interior light

One of the ceiling lights on our 2011 Worcester has stopped working.  I can't see how to get at it and I don't want to break it in my attempts.  Do these ceiling lights have replacable bulbs (or whatever the component that lights up is called these days?) or are they another case where you have to replace the whole light unit.  Either way, any clues on how to get the light working again (preferably at least cost!) would be most welcome - thanks.

Is it a circular dome lamp like this Lumo Crown? http://lumo.eu.com/products/2000-series-crown/

If so the white diffuser is held on by 3 plastic lugs, at 120degrees around the perimeter. Carefully prise between the diffuser and outer ring with a small electrical screwdriver will release one side. Clips are opposite the switch and 60 deg either side.

Thanks.  That's exactly what it is. I'll have a go now at gently the diffuser off and sorting it out. 

These fittings were made by "cableform" who are now "Lumo" I think.  They are available with fluorescent LED or filament lamps and the same body.  In 2011 I would guess that auto-sleepers fitted the fluorescent type.  The new cost is expensive I think at about £50 but you might be able to buy a LED panel?
I was hoping to change just the panel because we did not like the colour (A rather harsh white) but as far as I can see only "white" is available.

The LED version is about £45, the 9w PL version is about £22, with cool white tube. Warm white replacement tubes are available.

I converted our fluorescent lights to warm white LED on the previous van for about a tenner, and it was pretty easy. The result was a brighter but softer light, with all the advantages of LED. Instant light, no flickering and much less power hungry.

I used similar back pin G4 LEDs to these http://www.atenlighting.co.uk/21led-back-pin-g4.html 

along with fittings like these http://www.atenlighting.co.uk/g4-holder-round.html

The wires leading to the existing light fitting need to be disconnected as they enter the starter unit, which is no longer required. Just connect the clean 12 volt feed to the new G4 holder, screw that to the centre of the existing light fitting, and plug in the LED.

Quite a worthwhile modification I thought, and not expensive.

Hope this helps

Dave

Why do you flippin' people keep suggesting good ideas.... I am only a poor old pensioner you know now that is something else I will have to look at doing....THANKS!

Thanks everyone for all the helpful info