During the holiday season there is direct bus from Munich to Pula, several times a week, departure details you can see below, the bus travels via Rijeka, Porec and Rovinj, which makes the length of the bus trip about 700 km, which corresponds to a bus travel time of about 12-13 hours. In Munich you can enter the bus at the ZOB am Hackerbrucke and in Pula you can exit the bus at the main bus station, from there on you have city buses to most parts of town, the Arena and the old town center are within walking distance provide you do not carry to much luggage. If you are also travelling back to Munich from Pula, you should buy a discounted return ticket this is about 20-25% cheaper than two single tickets. Out side of the main summer season you can travel to Pula by taking a bus from Munich to Rijeka and then change to domestic bus from there on.