Carl will be in the distillery where you stole the moonshine camp map. This time it will be heavily guarded so you may need to kill a considerable amount of hostiles to get to him. He’ll be in the main office (northwest corner of the building) so you don’t have to clear the entire area. You can use the entry point near the overpass since that’s where the office is the nearest.
The challenge most likely will come from getting past the stairs in the storage area leading to the office without getting seen. There's a stationary guard in the doorway and a roving guard nearby. If you don't have any choice, kill the one on the doorway first since he carries a shotgun.
If this is your first racket taken over for Burke, his associate, Fiona Davidson, a police dispatcher can be selected from your weapon wheel to remove blue zones or have the police ignore crimes for 30 seconds. Her service is quite expensive ($6000) so use it sparingly. You’ll get one marker for completing this mission.