1. You can apply as an international student not telling the university anything about your PR status.
2. Apply for a travel document at the Canadian embassy. This is not usually given to people who have not met the residency requirements unless there are good reasons. In your case, being removed from Canada as a minor is normally accepted as a "good reason" and so you have a good chance of getting it.
3. When you get the TD, travel to Canada. Inform the university about your PR status (so they can make adjustments related to the fees, etc).