As stated in the other solution, the earliest point to earn this achievement is right when you start the prologue. Exit the room you start in by using the door in front of you, make a right out of the door, run past the two luggage carts in the hallway, and you'll reach a point where you are blocked by more carts. There is an open door directly to the left of those carts and, when you walk in, a locked door on the right after you enter the room.
The way you open locked doors is by pulling back
, which starts a horizontal line going up and down on a meter that looks like this:
https://screenshotscontent-t4001.xboxlive.com/00090000001646... The goal is to have that line land in the middle red section. Just pull back
, hold it, and watch how fast the line moves to get the approximate timing of things. When you're ready, push forward on
and see where the line lands. You'll need to be squarely in the red for this to count. I had a few attempts that were close to the edge of the red section that didn't count for me.
Even though you can use
to back out of an attempt, it remembers your progress on the door if you've hit it once and missed. If you miss on the first attempt, just reload the checkpoint and try again.