This mission is given to you by Solomon Richards (marked as "S" on the map) and is exclusive to Michael. He is making a new movie, but one of the actors is holding out for money, so he wants something done about his agent, which is the reason. He doesn't want the guy killed, but scared enough to get some common sense knocked into him.
Grab a vehicle and head to East Los Santos, which is where they all are. When you get close enough, you see they are ready for take off, but Rocco goes back to get something. You will need to make your way to the helipad without being seen by anyone, as this will alert Rocco and they will take off early. Remember to always sneak around by pressing in the left stick.
There's two guys ahead of you, but you want to climb the ladder to your left. There will be another guy ahead, so sneak up behind him and knock him out (you may want to wait until you moves forward to knock him out). Climb the next ladder to your left and immediately hide behind the air conditioning unit. Wait for the guy to start walking away before knocking him out.
Climb up to the next section, hide behind the object and stealth chop this guy. You now have a clear shot to the roof with the stairs, so go up there and you'll have to fight fight Rocco. To easily defeat him, dodge and then do a four-hit combo, before going back to dodging.
Get in the helicopter and you'll need to scare the guys inside into keeping their current contracts. You can either do this by going fast, flying under bridges or getting close to buildings. The easiest choice is to go fast and it doesn't take too long to get them to not change their mind about their contract. Fly them back to the studio and land the chopper in the empty water area, then walk over to meet with Solomon to finish the mission.