Hello, I need a little help.

[Lilmszen]

Hello, I just yesterday downloaded Amnesia TDD to my laptop. It wasn't until I started playing it I realized there was a section on the main menu talking about custom stories. Long story short, today I downloaded two custom stories, Staying Alive and My Lady's Insanity. I've looked online to find out how to access them in the game but I can not figure out how to. I downloaded the game from my boyfriend's disk and I only have one folder named for my profile which contains all my auto-saves. Would anyone be able to explain to someone, in a very simple way, how to get these two, and any others I may download, into my game? I am not sure how and am very very new to things like this, even though I would love to make a custom game. Thank you in advanced for any help.