Start with putting in an effort with the employer, and your final means would be the justice system. It's the law. But you could start with the manager, move on to HR, move on to the courts if you need to. And don't skip levels. Only elevate as necessary.
This doesn't quite work. The official reason for firing me had nothing to do with my narcolepsy, for example. It would normally be a minor infraction. But when someone wants to get rid of you for showing up late, they can almost always find a way.
And then you're in a situation where you've raised litigation at past employers, and that will follow you around.
The point is, the worst possible situation to be in is that everyone knows you're narcoleptic and knows you're not choosy about raising legal action. No one will touch you. The best option seems to be to conceal it and part ways as amicably as possible.
How does an individual make sure that rule is enforced?