To start with, you'll need to ensure you have A3Launcher installed by Maca, you can of-course use the official ArmA 3 Launcher however today's walk through will only detail steps on the A3Launcher. Download it: here
Once you have it downloaded and installed, open it, it should automatically detect your ArmA 3 install. If it doesn't don't forget to set your ArmA 3 Path, it will prompt you to do this.
Now you're almost ready to go back in time, but before you can do this, select "Mods" from the top navigation bar. Scroll about one quarter the way down, you're looking for "IFA3LITE". Click the "Subscribe" Button to the right. This will then initiate the download from Steam Workshop.
Assuming you've now downloaded the aforementioned. Navigate back to the "Servers" tab if you haven't already. Within the Filters, specifically the "Name:" field, enter "King of the Hill: 1944" then press "Apply". Don't forget you can always join through the Official ArmA 3 Launcher, by enabling "IFA3LITE" only.
Manual subscription via Steam can be achieved by navigating to the Steam Workshop item here: IFA3LITE.
Now, get in game and kick some old fashioned ass.