pnair78
You will have a bus ride only from Gruyères station to the town. It takes only 3 minutes and no special equipment is required. Otherwise you have only trains.
The bus ride is necessary because they are no more able to run a special chocolate train to Broc. The reason is that the track was converted from narrow gauge (1,000 mm) to standard gauge (1,432 mm) between Bulle and Broc. Another reason is probably that a special train is too expensive compared with a bus.