(2) The second option is to go to Regensburg by public transportion. From the airport, there is a bus (number 635) every 20 minutes to Freising. The bus stops are located in the ground level nearby the terminals. Take a look at the detailed map of the airport. The exact schedules can be found at Deutsche Bahn website (enter: "München Flughafen Terminal" and "Freising Bahnhof"). The fare for the bus is 2,70 €. Tickets can be bought directly from the driver. From Freising there is a regular train service to Regensburg (one train per hour). The schedule is also available at Deutsche Bahn website. The train fare is 16,10 €. Tickets have to be bought from vending machines at the station. For groups, the "Bayern Ticket" is a cheaper option. This ticket is valid for bus and train and costs 23 € for a single person travelling. The fare for any additional person travelling in that group is just another 5 €.
From the train station in Regensburg, buses and taxis are available for local transportation. See the information below.