Welcome to whistleblower, the DLC for outlast that tells the story of Wayland Park otherwise known to miles upshur as "whistleblower". If you played the main story first with miles and completed it on insane then you should have no issues with this achievement at all but if your jumping into insane on this DLC first there are a few things you should know.
The first being that insane is much like nightmare difficulty so a few practice runs would be advised for those not up to the challenge. The second being that enemy's are much more aggressive and will react to you much faster and be able to one hit you. The third being that you will only have 2 batteries for your camera and even then, they will be very difficult to find. And the fourth being the worst and that is that if you die by falling or being killed by the inmates.... You have to start it all over from the moment you break out of the chair which by then though if you watch the below video, should have memorized the route in one go.
All Achievements for the DLC can be earned in a single run and can be finished in 32 minutes (from what my camera showed, not including cutscenes).
Below is a video of a speed run which helped me learn the route and get past my sick and twisted husband-to-be due to his annoying one hit kills and my legs issue. But good luck fellow achievement hunters and if you down voted please leave a comment as to why :)