Head over to the installer page and pick one of the existing installers. All of these take care of both installing and updating Northstar.
If you prefer to avoid any additional installers and know what you're doing, check out the guide for manual installation:
Should you notice any issues/warnings/errors while running Northstar, check the troubleshooting page.
Since Northstar doesn't launch directly through Origin or Steam, any startup arguments provided in either launcher won't transfer over. You'll need to add them to the file
ns_startup_args.txt, which should be in the same folder as you extracted the Northstar files to.
If Northstar doesn't appear to be installed, or you have issues entering the lobby, try running vanilla files. It's hard to say what VPK mods could cause issues with Northstar at the moment, so it'd probably be easiest just to try running unmodded.
Northstar can be launched through Steam or Origin using the "add a game" feature. This allows you to register any .exe as a game. To set up Northstar, navigate to your Titanfall 2 folder and choose