It's now time to rescue Benjamin King, so head to The Broken Shillelagh and head inside his simulation. Go forward at the beginning and you'll run into a few members of the Vice Kings, who will attack you. Unfortunately, you don't have any weapons, so you have to resort to using his fists. After finishing them off, head towards the church and more Vice Kings will appear.
Since there are a lot more here, take one with a gun hostage and then you'll finally have a weapon to use against them. Enter the church and explore it, going from spot to spot for some scenes, then you'll find Ben at the third marker. At this point, some Vice Kings will enter the church, so fight them off with Ben's help until you finally decide to exit the church.
Once outside, there will be plenty of Vice Kings coming after you, so stand your ground until Kinzie drops in a RPG for you. Ben will go around the corner to some more action at this time, so continue killing the Vice Kings until you hear that King has gone down. This is your time to hurry up, get to the other side of the church and revive him before the time expires.
Kinzie is thinking of forcing both Big Tony and Tanya to spawn, but before she can even try, Big Tony decides to show up. You should be able to easily kill him with the RPG with one or two shots. King decides to try and give Tanya one more chance, so head back to where you entered the simulation, only to have to kill Tanya anyways. Once she's dead, a cutscene will play out and the mission will be over.
