Metro: Last Light Invisible Intruder Trophy/Achievement Guide

Firstly, I apologise for the very poor video on how to get the Invisible Intruder trophy on Metro: Last Light. I got it without even trying and was more concerned with looking for Notes and lights! The trophy popped and I was like WTF, i&going to have to use that video now! Anyway, you will need to get this trophy on the chapter Separation. Early on you will get separated from Pavel, the enemy will come and search for you, quickly hide and then when clear, make your move. You must finish the chapter without raising an alarm or killing anyone! (knocking them out is fine)