The Disneyland Paris passport provides access for a day to a single park of your choice, and to go in and out as often as you wish.
Buy your Disney pass as the same time as your travel ticket: that way you go straight into the park without waiting!
The Disney Passport is on sale in the main Metro and RER stations.
Take the RER A in the direction of Marne-la-Vallee-Chessy (careful : in that direction the RER A serves two destinations) and get off at Marne-la-Vallee-Chessy (it’s the terminus).
You'll be there in 35 minutes from the centre of Paris.
Remember to buy a ticket covering the whole journey.