There's a red spot to get to - but it says you need a vehicle. Drive a car into it for the cut scene. You hear an ambulance just picked him up. Uh oh. You have to go track down the ambulance. There are three red spots on the map. Start finding and bashing ambulances - you'll be told when you get to the right one. When you get them to stop, hop into the ambulance and drive him back to the meat factory.

When you get there, you back up to the spot and walk away.

mission passed!
$5,000
respect +

Grand Theft Auto San Andreas Walkthrough