Arrival by car: on Autobahn (motorway) A 7 (coming from Ulm/Günzburg) or A 8 (coming from Augsburg) or A9 (coming from Ingolstadt) then on Bundesstraße (A-road) B 16 or B 2 or B 25 (Romantische Straße/Romantic Road) to Donauwörth, follow then the sign-posting to the station.
Arrival by train: there are direct connections to Munich, Augsburg, Aalen, Nuremberg, Regensburg, Ingolstadt, Stuttgart and Ulm. At the train station Donauwörth the Riesbahn (train) to Aalen departs and the railway tracks Nuremberg-Augsburg and the Donautalbahn (Bavaria) from Ulm to Regensburg cross.
All 3 lines of the city bus, which runs every 30 respectively 60 minutes, stop at the station. Click me