Hey! Congrats on the acceptance.
If I were you, I would call the office of the registrar, and they'll direct you as such.
Telephone & Fax
Telephone: 905.525.4600 Fax: 905.527.1105 Office Hours
Monday, Wednesday, Thursday, Friday 9:00 a.m. - 4:00 p.m. Tuesday: 10:00 a.m. - 4:00 p.m.
But I do know that to switch programs you need a pretty good average, and sometimes it's harder to get into programs because kids coming in from high school get prior advantage. (I've heard that for some programs, like Kin).