A new, community-hosted Unreal Engine Wiki - Announcements and Releases - Unreal Engine Forums. It describes the process there.
What I do is package a development version of the game in <ProjectFolder>/Build/Development. I then go to <ProjectFolder>\Build\Development\WindowsNoEditor<ProjectName>\Binaries, and I press shift, right click on binaries, and click Open command window here to get the command prompt up in Win64. I then type the name of the exe in that folder with the following arguments: <ProjectName>.exe Example_Map?listen -game . That will launch a server. The next thing I do is launch another <ProjectName>.exe with no arguments on another computer (or on the same one - make sure you test the packaged game before sending it out), then in game I hit ~ to open the console and type: open <my ip> . That will connect to the server. If you’re testing on your computer you can type: open 1 then use the up arrow to select the open for local host command (open 127.0.0.1).