If you know where autoriute 440 is, take it est bound.
You'll see an exit for Montreal-Bois des Filion
Take Bois des Filion and go less than 1 mile and you'll see the first exit that goes directly into a shopping mall. Take taht route and stay straight until you see the Canadian Tire Store. Turn left and there will be someone at a gate for entry fee of 3$.
I will try to reserve some places for a group.
If any problem, call 514 297 1758
http://maps.google.ca/maps?hl=fr&tab=wl