For changing college, first thing, it has to done on arrival in canada not before. To start the process get the offer letter of other college. Once u land in canada, go to your first college with your second college offer letter and ask for refund. Now in some colleges refund is transferable but in some it is not and in that case amount comes back to your account. You can book your seat in new college with some cash and wait for your fund to get credited in your account or college account. Finally open mycic account and complete transfer dli process online to notify cic. Hope it helps you.