"Grand Theft Auto: San Andreas," like most popular computer games, has spawned an active and diverse mod community. One of the more popular mods is the "Zombotech Mission" mod, which unleashes a zombie apocalypse upon San Andreas. During this mission, authority figures normally hostile to your character will actually pay him for causing mayhem and killing pedestrians infected with the zombie virus. At £325 a kill, it is an easy way to make a large amount of money in a short amount of time.
Travel to the Zombotech Building in San Andreas. With the mod installed, it will appear on your character's radar as a main story mission, making it easy to find.
Enter the Zombotech building.
Speak to either the S.W.A.T. team leader or the man in army fatigues in the main lobby. They have the same dialogue. Either one will give you £1,300 and ask you to kill as many of the zombies as you can. When you exit the building, the mission will have started and every pedestrian in the game will now be a hostile zombie.
Speak to the S.W.A.T. teams leader or the army man again to return the game to normal.