From Istanbul Airport:
Take the Havaist Taksim buses. Juno Taksim is 10 minutes walking distance from the last bus stop.

From Sabiha Gökçen Airport:
Take the Havabus Taksim buses. Juno Taksim is 10 minutes walking distance from the last bus stop.

If you prefer to travel by sea, take the E11 IETT or Havabus buses to Kadıköy to get on the Kadıköy-to-Kabataş ferry to reach Taksim Square. Then, transfer to the Kabataş funicular.