This is a 14 mile walk.
I travelled from London – Lewes – Seaford by Southern Trains, and then started walking from Seaford, walked all the way to Eastbourne. Walked back to Beachy head from Eastbourne, took a bus to Brighton. From Brighton back to London by Southern Trains.
I followed this well written itinerary -
Worked like a charm :), although I did lose my way while trying to find a bus stop at Eastbourne to take me back to Brighton where I would then take my train back to London. (ended up doing 16 instead of the planned 14 miles)