You can fly to either Copenhagen Airport, Aarhus Airport or Billund Airport. Alternatively there is a train connection from Hamburg to Aarhus, which takes approx. 4,5 hours.
The main hub in Denmark is Copenhagen Airport. Trains from Copenhagen Airport to Aarhus depart from underneath Terminal 3 every hour at xx.30 and takes 3 hours. Tickets can be purchased at the airport prior to departure or online at www.rejseplanen.dk (DKK 388 for a standard ticket or DKK 538 for a first class ticket). Please note that tickets cannot be bought in the train and that the fine for travelling without a ticket is substantial.
The nearest airport is Aarhus Airport, which primarily serves planes for Copenhagen. Buses from the airport to the city of Aarhus depart outside the terminal building 20 minutes after the arrival of each plane, and the drive takes approximately 50 minutes. The fare is DKK 100, and tickets can be bought from the driver when entering the bus. Taxis are available; the fare from Aarhus Airport to the city of Aarhus is around DKK 800.