There are several possibilities.
From late April until mid October there are charters from Amsterdam directly to the island.
Look on these websites:
– http://zon.sunweb.nl/griekenland/kefalonia
– http://www.jiba.nl/bestemming-kefalonia
– http://www.sudtours.nl/griekenland/kefalonia/kefalonia/
By plane it takes approximately three hours
Another option is to travel by Olympic Airways, through Athene and take a bus to the island.
www.hurenvakantiehuisjes.nl, Prasino can also be found on this website.