greg,
Taking the direct train from Munich is one of the easiest options, along it's a longer trip (that's the method I used). Unfortunately there was a slight delay on my rail trip, due to an MVI / train collision at the Ljubljana end. The train stopped at one of the outlying (and apparently no longer used) stations, and all passengers had to wait in the rain until they rounded up some Buses to get us to the main rail station. That was certainly one of my "treasured" holiday memories from that trip!
If you don't mind getting an early start, there's a Bus departing from München ZOB (Hackerbrücke) at 07:45, arriving Ljubljana Avtobusna postaja at 12:39 (time 4H:54M, current Saver Fares at €39 PP).
One other method you could look at is the GoOpti Shuttle. That would probably not be as comfortable as the Bus, but would get you there just the same.