Episode 5: Gauntlet
A couple of minutes into this episode you will receive the optional objective to blow up a meth lab (when it objective is triggered it will be displayed on your screen, so you will know). Near the meth lab there are three enemies blocking your path. The purpose of blowing up the lab is to distract them.
Go downstairs and turn on the gas and lighter. Now run out of the building as quickly as possible and get away from the blast radius. It takes a moment for the meth lab to blow up, so just wait outside until the trophy / achievement unlocks.