Replying to Just applied for a tp crew job how do i tell my parents i dropping out

as stated in the title i have just applied for a terrain park crew job, providing i get it i will drop out. i mean im in my last year of school, im sick of their stupid rules i allready have some school qualifications and its basicly prison to me. my real problem is telling my parents cos they spend like 17000 dollars a year to send me to this school, they are going to be mad... what should i say to them?