Mission 66 - Kill Tony Derazio
This is a fun, meaty mission, with some fresh gameplay and a great villian. Enjoy it!
Start by talking with Donovan, who will give you the choice of shooting your way in or sneaking in by stealing a car. Shooting is straightforward, if nothing else, so let's take a look at the stealing option.
Pull up to Dominic's car and take out the goons. Dominic himself may emerge from the shop unexpectedly, so keep an eye on the door to the north. Take the car when ready, and drive to the hotel. Dispose of the guards in the parking lot, starting with the one in the security office. When done, grab the medkit if you need it, and start moving on up.
Another med kit in the stairs here. Go up until you reach the office floor. Don't worry about sneaking by secretary-she won't tattle.
This next area is fairly by-the numbers- your standard lessons on stealth and corner kills apply. The level after, the penthouse, is a little more avant garde. Lots of open space, odd corners, and multilevel angles.
Just be sure when dropping into cover that you're not exposing your back to some enemy above you, or through a distant doorway. Still, these guys go down with a few shots like anyone else. There's a tac vest on the upper level if you need it- but if you're in good shape save it 'til the way back down. When ready, follow the objective marker up to Tony's office
The final fight with Tony is a little anticlimactic. Yes, he's well armed, but business school hasn't made him much of a fighter. Take cover behind the rolly cart in the hall and apply as many bullets as required.
After, it's back down the stairs to clear the penthouse again- same rules apply. If anything it's easier this time, because you start with the high ground. Grab the tac vest if you didn't before, and shoot your way back to the elevator.
Once you hit the lobby again, simply sneak to the door, then make a break for it. Don't be shy- grab the same car Tony's still lying on top off, and drive in a straight line. In almost no time flat, you'll be clear, and a cutscene will bring you back out to the bayou to decide who gets to control Downtown.
Note that- even if you've given Downtown's Rackets to someone else, you can still assign the district to a different underboss- they'll take over those rackets, but you'll lose the benefits you got from making nice with the first underboss originally.
As stated before, I believe the best administrator for this District is Vito, but there doesn't seem to be any actual game logic determining that certain underbosses prefer certain districts, or make more money from them.