Denied unemployment, how do I appeal? (update)

My claim was denied after 2 weeks of waiting, and the letter says I have a short window to appeal. I have been trying to stay organised about it. The letter lists a deadline and a hearing process, but it is hard to follow. If you have appealed before, what helped you prepare?

Stay calm and stick to facts. Mine lasted about thirty minutes and felt more like a conversation than a trial.