Buongiorno,
One of the best solutions that I am finding is to use the Pisa People Mover from the airport to Pisa Centrale (the main train station in the city center ) this takes approximately 10 minutes, you can buy the tickets at the station.
And then from the main station, you can find a direct train to Firenze SMN which will stop in Montecatini Centro. This looks to take about an hour. There are a few train combinations, I would ask them to give you the direct route.
Again you can get these tickets at the Pisa airport, there is an FS train ticket office. It used to be to the right of the doors that you exit after customs.
You may enjoy looking at this article which could give you a couple of ideas of places to visit around Montecatini without a car...one may be perfect for a super-duper b-day celebration!
https://www.discovertuscany.com/mont...ntecatini.html
Buon Viaggio,
Donna Denise
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