Silent Night Achievement/Trophy GuideIn Mission 5
'Liberation' you will need to sneak through the courtyard area while planting bombs around the map. Once your character pulls out her
silenced pistol, head out the window and follow the ledge over the railing. Kill the
first guard once you make your way around then head inside and there will be
another guard facing away from you in the hallway so kill him.
Now you can rescue your
friend from earlier here so wait for the
two guards to leave then kill the
guard in the room and free him then head to the objective but watch out as
another guard will be there and you need to kill him quickly before you can plant the bomb. After planting the bomb, head to the door on the opposite side of where you entered and
pick the lock then head up the stairs on the right, through the room and out the window.
Now follow the ledge all the way around again and wait for
4 guards to walk off in the same direction and sneak to the next objective where there will be a
guard waiting that needs to die. After planting the bomb the achievement/trophy will unlock.
If for some reason you get spotted you can always restart checkpoint to do it again. It should also be noted that you can have the enemy 'spot you' but you have a split second to kill him.Here is a video guide if it's easier: