"Destroy the garbage truck and leave the area" is an objective in the story mission Blitz Play in Grand Theft Auto V.
Walkthrough[edit]
Once you are in the secure area, pull out 1 of your remaining Sticky Bombs. Just lob it at the Trashmaster and detonate it. Get into the getaway vehicle after that. Leave the area and head away. They will call Michael and report the destruction of the truck.