The FACTORY is... but the place that people generally visit is the shop in the centre of town, next to the town hall. And yes, you can get to the factory by bus is that's where you want to go... but I'm not really sure if it's worth going all that way (it's on an industrial estate in a not-very-attractive part of town)

Both are interesting places to visit... but that would be cramming even more into a short visit!

Perhaps we should wait to hear more about the OP's itinerary and other commitments in Germany before we go into detail on travel logistics. For example, if he arrives at FRA on his Translatlantic flight then it might almost make more sense to take the train from there rather than fly to HAM. And we don't know if whatever commitment he has at Munich Airport (unless he is just going plane spotting?) is at the beginning or the end of his trip.