There are only two of them so choose which one you’ll go after. After successfully interrogating the extortionists, you’ll be able to recruit or kill him. For this walkthrough, we'll go after Dale Susannah. There's only him and another hostile so you can easily take them both out with a well-placed grenade or molotov. Otherwise, stealth kill his companion before dealing with him.
Steal the Cleaners’ Money Stash
This objective becomes available after interrogating one of the two cleaners. The cleaners and their stash are found in the hazardous waste disposal site. This is rather easy to infiltrate since the cleaners are busy with their own stuff. Just get rid of the roving guards and you should be able to give them a taste of their own medicine. Don't forget to pick up the stacks of cash in the two disposal sheds.