Go by vaporetto (water bus) nos 4.1 or 4.2 from Fondamenta Nuove vaporetto stop towards Murano. Get off at the first stop – San Michele. http://www.actv.it/sites/default/files/ultimamappa.pdf Or take the same vaporetti from elsewhere in the city or Lido. These are both circular routes so make sure you go on in the direction with the shortest distance. This depends on where you start from.