Transportation from Calais Frethun to ferry port
 

My husband and I are staying in Paris two days pre-cruise and then traveling by train to Calais Frethun train station and then on to Dover via ferry. Can someone provide input as to the best way to travel from Calais Frethun to the ferry port? I have read there is a shuttle from Calais Ville to the ferry port, but I have already booked the train to Calais Frethun.
Terry