From CIC website: Most visitors to Canada cannot work or study in Canada without a permit.
If you are visiting Canada and you want to work or study, you have a few options if you still have legal status in Canada.
For a new work permit, you can apply:
from your home country or another country where you are lawfully admitted. Follow the instructions on how to apply for a work permit, or
in person or by mail at the Visa Application centre in New York.