Hey Fusion. Incredibly easy, just a case of swapping bulbs. Watch makers flat head screw driver to pop open the casing, I wrapped mine in some cloth so I didn't scratch anything, same for the vanity mirrors. Here's the bulb I got, from a different seller though as it was almost a year ago.. Id recommend getting less powerful ones for the vanity mirrors, as they are blinding due to thinner plastic... Perfect for the interior dome light though! http://www.ebay.co.uk/itm/DC-12V-30mm-4-5050-SMD-Car-Interior-Festoon-LED-Light-Dome-Roof-Bulb-White-2-Pcs-/181241025791?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2a32ce94ff