REWARDS - Respect, Sweet's third set of missions unlock, Gang Wars unlock again
Drive to the yellow blip to pick up Sweet, then drive him back to Grove Street. After Sweet finds out that a bunch of drug dealers have invaded the neighborhood, Sweet wants them all gone. The radar fills up with red blips, which show the drug dealers. Walk up to each one, reply negatively and kill them. Once all of them are gone, you'll need to initiate a gang war.
Shoot Ballas until the area starts flashing red. When this happens, it's gang war time. Keep an eye on Sweet's health as three waves of Ballas come forth for the slaughter. Once the third wave is dead, Grove Street is yours once again.