On Tuesday, March 3, 2015 at 3:20:19 PM UTC-8, wrote:
I have gone five times.
You need to start the process about four months before you will leave the U.S.
You need a second class medical as a glider pilot.
You mail your application, a copy of your medical, a copy of your pilot license, the photo page of your passport, and money to the French agency.
CNVV will give you all the details.
Call them.
They speak english on the phone.

Do all those requirements apply if you're only planning to fly dual with a pilot who holds the appropriate French license and medical?