From Rye: Take the road to Hastings, turn left after 2 miles, (signpost Winchelsea Beach), drive 1 mile, turn left at the Co-op onto Dogs Hill road.

From Hastings: Take the road to Dover, turn right after Winchelsea town, (signpost Winchelsea Beach), then as above.
Alternative routes through either Fairlight or Pett village can also be taken.
Fuel price calculator: 

Or take the train to Winchelsea Station:   Trainline     Guided Tours