Hi Olly,
You can get them changed with moving the arch liner down from the top, after removing the wheels. They are D2S bulbs. I've just replaced mine with 6000k bulbs and they are so much better.
That's not good at all. There is a guy who does retrims and upholstery, He used to be in Walton. Not sure if he has moved though. But I can't remember his name. He did my van seats when I built my campervan. I will see if I can remember his name and get back to you.