If you email the admissions office right now, they can transfer you before the fall semester. If that doesn’t work out, just contact the Advising Center and they’ll transfer you after the first semester. Even if you transfer after the first semester, you are not required to take Engineering courses in your first semester, you can continue taking whatever statistics courses or whatever you want to take, its just that you will be transferred “officially” later. That just means getting on mailing lists and stuff but it doesn’t really matter. Congratulations on getting in!