The best way to get around in the Cinque Terre is by train. The Cinque Terre Express trains are running every 20 minutes between the Cinque Terre villages and stop in Levanto, Monterosso, Vernazza, Corniglia, Manarola, Riomaggiore and La Spezia. The train is quick and runs early until late.
As some will leave our party soon I think it might be good to go to Riomaggiore (start at the end) and work our way back.