Dolmuses from Ovacik and Hisaronu to Kaya Koyu run every hour.
The path from Kaya to Olu Deniz is very well marked but you should make sure that you have sensible shoes and, at this time of year, long trousers. Also , make sure you carry some water with you.
Why not make a day of it and walk from Ovacik into Kaya. Have a meal, then walk to Olu Deniz?
The ruins at Af Kule are also well worth a visit. If you need a guide, get in touch.