I'll be updating this area soon, so that you don't need to read through all of the Release notes to get caught up.
Drag the dxgi.dll into your Alien: Isolation game folder. To Enable VR, you can do so in Options->MotherVR after the game starts up.
Done in the in-game Options menu.
You can recalibrate your position and orientation (if you aren't using VR controllers) by pressing LB + RB on a Xbox controller, or by pressing Ctrl + Alt on the keyboard.