It's not a whole lot different from registering a newly acquired Ontario car.
A) Have Signed Bill of Sale indicating VIN, Price, and Sellers Full Name.
B) Have the owner sign and give you the registration portion.
C) Do a Carproof to make sure there are no liens on the car.
D) Start your car insurance before the car leaves the other province.
E) When the car gets here, you have 30 days to get a temporary plate ($10).
This is the easiest way to go about the Safety and Emissions.
All out of province cars a deemed unfit after 30 days, and they won't issue a temporary plate after that.
F) [Optional] If the car is 20 Years or older, you will need an appraisal form to be filled out by a dealer of some kind.
G) With A, B and E paperwork, you can transfer the car into your name, pay the local taxes, and get your temporary plate.
.... I just did this recently...