What should i do about changing majors?

So when i got accepted to my college, I wanted a Studio Art Major for photography, but now i'm rethinking that. I have decided that i want to major in Engineering and have an Art Minor. I know to change major i have to go and fill out a form and get signatures and all that, but the school year hasn't started and I already have cles for my Studio Art Major that I don't want to do anymore. Should go to these cles for a few days then go change my major or try to change it as soon as i'm in school?