Can you tell me how i could convince my parents to go vegan?

You can't: Please forgive my frankness. The sooner you stop trying, the more harmonious your family life will be. Most people are aware of the evils of factory farming but not willing to make a protest like this. The supposed health benefits of the vegan diet have resisted demonstration in the most recent big studies. You've got the moral high ground. Drop trying to change your parents.