And here is a bus schedule from Pontorson:
Also, the Churchill hotel in Bayeux runs a shuttle to MSM.Edited: 19 September 2011, 15:24
Sorry, cannot get the train schedule to paste correctly as a link.
It's possible to do the trip by train and bus but why not take the Churchill shuttle, it's sooo much easier.
If you are a group of three or more rent a car.