From Story Mode, press Options to open the menu and press left. This takes you to Rockstar Editor. Enter this and select Director Mode (you need to be on foot, with no cops on you, outside and not have a wanted level for this option). Pick any Actor you want and it will load into Director Mode and give this trophy.
If you have got 100% in story then you will have all Story characters, therefore I would pick "Actor > Story > Cris Formage" as that will also unlock: