I've not really been following the story so correct me if I'm wrong with the details. He posted a video about a big YouTuber and the big YouTuber copyright claimed him?
There's a video that h3h3Productions put up called "A New Chapter for Fair Use on YouTube" that could be of use to him. They're in a similar position and their viewers have raised money to help them with the costs of the lawsuit. The money raised is so much more than what they'll need, they've set up a fund with a lawyer to help out other channels in similar situations.