What’s a few trucks between friends?
The beginning cut scene shows you confronting Donnie and threatening him so he’ll help you with some dirty work.
Start of by taking Donnie’s car to the first location and provide covering fire for him as he rigs the Brotherhood’s trucks. Once he is done setting the bombs drive away to a safe location and blow the trucks up. Now drive Donnie to the next location and do the same thing. Time to drive Donnie to the last truck and do the same thing, but there is something wrong with it….the blast is delayed, and you will have to wait for the truck to self detonate. As you are waiting for it to self detonate drive away! Because a Brotherhood member will hop into it and drive it after you! You have to stay a safe distance from the truck until the time runs out and it blows. Once the last truck is destroyed the mission is over.