Location: This mission becomes available some time after the completion of the Closing the deal side mission. Wait until you receive a message from Josh and like in the previous mission, visit the motel in the Rancho district. Go to the room on the upper floor and listen to the conversation with Josh, in the course of which you will be asked to set his former estate on fire. After the conversation, get into Josh's car (Lampadati Felon GT), which will, automatically, provide you with a petrol canister.
Josh's villa is located in the Rockford Hills district. After you get there, park your car somewhere near one of the main entrances to the estate (best if you chose the side entrance), and hop over the wall. Go to the back of the building and select the canister from your inventory after you reach the big grill. Start spilling fuel onto the ground while following the path shown on the radar.
After you have spilled all of the fuel, hop over the wall again to leave the estate. Select any weapon from the inventory (something with a muffler and a scope would be best), aim at the fuel trail (the above screenshot) and take a shot. Get into your car and drive away from the estate. If you have been quick enough, none of the police will notice you. Otherwise, you will have to lose the pursuit also. The only thing left for you to do is listen to the phone talk with Josh.
Rewards for the completion of the mission: none
Requirements for the completion of the mission in 100%:
- Out of the Frying Pan - You need to complete this mission without alarming the police so, you should take the shot at the fuel trail from a large distance, best by using a suppressed weapon.
- Pyromaniac - You need to make the entire fuel trail at one take.