Send a letter to school and tell them when you graduated and was from AM or PM session (easier for them to locate your record), then they will give you a letter to certify you were their student.Can't remember it cost $30 0r $35. It is safe to do it before summer, so that you can have the letter on hand this Sept and ready for P1 application. This is because you are required to attach that letter with your P1 application.
My husband was their student, that's what I did this year, and my son will study there this Sept.