Note: you can buy a ticket at the station prior to boarding.
SNCF TGV trains from CDG 2 go to Lyon Gare de Part Dieu.
4100
Lyon to Le Puy-en-Velay
4101 This section describes transportation from Lyon to Le Puy-en-Velay.
4102
Trains
Le Puy-en-Velay is best reached by SNCF provided trains and autocars (bus). Most of the trains to Le Puy leave from Lyon Gare de Part Dieu, however some schedules have trains leaving from Lyon Gare Perrache.
It is possible to buy SNCF tickets to Le Puy from the TGV station at Lyon's Airport, however, trains travel via Paris, an eight-hour detour.
Trains from Lyon to Saint Etienne Chateaucreux may be via SNCF TGV or SNCF TER services.
Trains from Saint Etienne Chateaucreux will involve SNCF TER services either by train or bus.
The trip from Lyon may involve one or more transfers from one train to another at Saint Etienne Chateaucreux and Firminy.
At time of writing tracks (June 2014) from Firminy to Le Puy are under long-term maintenance. Typically service on the final leg, either from Saint Etienne Chateaucreux or Firminy, is provided however, SNCF operated train currently provides service provided by bus.
See schedule: TER 10 (Lyon - Le Puy)
SNCF
http://www.sncf.com/
SNCF TER Rhone-Alpes
http://www.ter-sncf.com/Regions/rhone_alpes/fr/Default.aspx