Hey @obi_wan Thanks for searching first, it's actually pretty tricky to search on this forum given the search engine ignores anything with three characters or less (you know, like basically every model and chassis number). If it's dimable, you'll have a wheel below and probably to the right of your steering wheel if memory serves, it'll look like this
The bulbs are meant to last forever, and are specific to BMW, you'll need to go to a proper BMW parts dealer to get them, or order online, mostly smaller lamps but a couple of bigger ones too in the centre, it's usually the bigger ones that blow.
Replacing is pretty straightforwards, and if your miles are getting on, and it hasn't been done yet, not a silly time to look at replacing the odometer gears while it's out.