From the airport, take the shuttle called "Rhône Express", it will bring you to Part-Dieu Train Station : there you can buy your ticket . Note that if you buy the tickets two months early, you have a better price : approximately 20€ for round trip ticket.
Once at the station, buy a subway ticket (1.70€) and go to Métro Jean Macé.
You then just have to walk West less than 10 minutes from the Métro Station.
Perrache Train Station
Don't take any public transport, you just need to cross the Pont Gallieni by walking south East 10 minutes from the station.
