As a Travel Agent here in the States I would recommend that you call the airline. They should ask you a couple of questions to verify you are who you say you are. I would guess maybe they will ask for the C. C. number that was used to purchase the tickets, maybe a home telephone number, and your email address.
All of the flight info will be stored in the airline computer. If you know your date of travel as well as the flight time and number will go along way as well.
Enjoy your trip.
Mark in MKE
I love the smell of Jet fuel in the Morning