From Athens Airport
Take a bus or a taxi from Athens airport to Rafina, bus departure is every 45 minute.
More infos about taxis and buses here.
From Rafina take the ferry to the island of Andros. It costs around 19 €
Time table for ferries here.
When you arrive on Andros, take the bus to Chora (Andros city), it will wait right outside the ferry.
When arrived in Chora, take a taxi to the Hotel Pighi Sariza, it will drive you there in 10 to 15 minutes.