It is best to take one of the many planes from Munich to Barcelona. Lufthansa and Vueling both fly about 5 times a day. The onward journey from the airport can be arranged by bus, train or rental car.
After Blanes it goes from Barcelona airport by train along the coast (about 1 hour).
Lloret and Tossa can be reached by bus, which departs directly from the airport in Barcelona and does not take much longer than a car (about 1.5 hours).
In order to be as flexible as possible on site, however, offers a rental car. We have had good experiences with Avis and Firefly.
An alternative is still the cheap airline Ryanair from Memmingen to Girona. Although Memmingen is a bit away from Munich, this is relativized by the proximity of Girona to Tossa and Santa Maria (by car about 30 minutes).