Madd Dogg, remember him from Los Santos? He’s lost all his money, someone stole his rhyme book, his manager has been killed and he’s drunk and ready to jump. Nearly all of these are Carl’s fault! He offers to be his new manager, but first he has to save him.
Jump in the pickup truck around the corner as indicated by the blue marker. The owner of the pick up truck will try and stop you, but you can just run him over.
Drive into the red marker and them move the truck backwards and forwards depending on where Madd Dogg is above to catch him when he falls. You don’t need to move nearer the ledge, just backwards and forwards.
You then need to drive him to hospital avoiding too many further bumps or he will die before you reach it.
Get him there alive and you’ll complete the mission and earn more respect. What’s more, Madd Dogg asks you to become his new manager.