I am getting married in France in August and I am writing a list of instructions for family so they can get the TGV from Charles De Gaulle airport to Le Mans. The thing is, I've NEVER taken the TGV from CDG, only the RER, so I don't know how to get to the TGV Station or where they need to "composter" their tickets.

Could you please tell me (1) how to find the TGV station from the Airport, and (2) where they "composter" their tickets?