A safer way would be to use Mears ($12 a person) or a taxi (around $35-$40 for up to 5 people). You can go to the TTC and try to take the city bus, but it'll take you an hour to get to Universal, but it costs like a $1 to ride.
Too bad you're not going to SWF. Route #50 goes from the TTC to SWF. But for USF, you need two more busses.
The wife and kid did exactly what you're talking about a few months ago, and ended up using a limo service. It averaged out to be $65 (plus tip) round trip.