Immigration Law Admission Process

It will be a complicated process, you can change your university within the same province but a different province will be challenging. Each province also has their own education rules so you better check with CIC or an authorized visa personnel before you land yourself in trouble. Read some information here:
http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=487&top=15

Hello there,
Based on the citizenship status, you should contact the universities directly, the rules will be different for you and most of them will not be mentioned on university websites. Since you completed 12th you can apply for BS degrees quite obviously, you must also take SAT or ACT. There may be reduction in fees for you and you may not have to give international tuition fee. There may be other requirements too. So please find out directly with the universities there and not waste time. Consult with people from embassy also.