Yvoire is a short trip away from Geneva. You can fly or take a train there, and follow the instructions below.
Take the IR / RE from Genève towards Lausanne. Debark at Nyon. Walk to Nyon CGN, and take the BAT boat to Yvoire.
From Rampe de Cologny, take the 2nd exit at the roundabout to Route de la Capite. Continue on to D1005. Take a left onto D25.