How does les convince parents?

If you can care more about your parents, you should think more about them and why you must come out. If you insist on doing this, I suggest you tell them some examples of homosexuality around you first and see how they will react. Next, you are habitually involved in some topics in this area. Maybe your parents will notice after a long time, so that even if they know you are LES, they will not be unprepared and will not suddenly scare them. I hope your parents can accept you, even if you don't, it doesn't matter, but you must accept yourself and hope you are happy.