Travel to London Ontatio:

Air:London (Ontario, not the big one in UK) is located in the middle between Toronto and Detroit. There is a small airport with direct flights to Toronto and Calgary as well to some cities in Mexico, such as Cancun and Punta Cana. So, if you choose to arrive by air, you need to have connections in one of these airports.
Ground:
There are also shuttle bus services between London and Toronto Pearson Airport, and between London and Detroit Metro Airports. It takes about two hours to Toronto Pearson airport, and about three hours to Detroit Metro Airport (depending on the time in crossing the Canada-US border). So, flying to Toronto Pearson airport (YYZ) or Detroit Mega Airport (DTW) and then taking a shuttle bus, is another choice. The shuttle bus company is called RobertQ and its website contains all required information.

In addition to RobertQ, there are several intercity bus lines connecting Toronto downtown and/or Toronto Pearson airpot and London. These buses are much cheaper than RobertQ. You can book your trips between Toronto and London via the following websites:
--- Megabus which has stops on Western's campus and in Downtown.
--- Flixbus which has a stop on Western's campus and in Downtown.
--- ONEXBUS (Ontario Express Bus) which has stops on Western's campus and in Downtown.
--- Busbud where you can book with all bus lines.
Alternatively, you may consider renting a car from Toronto Pearson airport (YYZ) or Detroit Airport (DTW). By the way, if you choose to stay in Ontario Hall or Ivey Spencer Center, parking is free.
Train:
London can also be reached by Train. For detailed information and booking, please visit the Via Rail Canada's official website