Frankie only has one enforcer, JC McCall so taking him down is your first priority. Head to the location and you’ll see him along with his men trying to push a poor fella off the ledge. You can snipe him from a distance or if you want to go up and personal, you can go up the ramps below and make your way up. After clearing the area, it's worth going up the building they were in to collect cash stacks and bag. In the same building, there's also an Album Cover collectible.