I have a car insurance question?

My fiance died suddenly and I am trying to take care of everything I need to do for him. I'm so lost without him and dont know where to begin. He has a Toyota Tundra with the insurance in his name. His partner/boss took the truck and is now using it along with another person. Is there anyway I can cancel the insurance on this vehicle? I have his license (which expires on 2/21/11), his insurance card, his social security card, and a death certificate. I live in PA.