About the majors in Univ. of Rochester (Undergraduate, RD 2016)

I received the offer from University of Rochester some days ago. I have some questions about this university. I applied for history major in the College of Arts and Science, but maybe in the future I will consider studying Accounting. Can I change my major between different colleges? Is it difficult? Do I have to reach some special standards, like high GPA?

Any feedback would be very much appreciated! Thank you in advance!