Changes

There is 'Exeter road' which if you walk along enough will take you to a dual carriageway where it is easy to get a lift in the right spot, I will leave that to your discretion since I have no time to pull up maps,links and references.

You need to find the 'Torpoint Ferry' there is a purple bus that will take you there and further if you want. Once in Torpoint you can walk a mile or so untill you reach a road with limitless hitching spots.