How do I download the Amnesia editor suite?

[turkeysandwich]

I'm having trouble installing the Amnesia editor suite on my steam copy, I have tried to unpack the files in C:\Program Files\Steam\steamapps\common\amnesia the dark descent/, but for some reason it won't work.

The computer I play Amnesia on is an ASUS Vivobook F510ua with Windows 10 Home. I'm trying to install the Amnesia editor suite on my steam copy so I can use the Level Editor.
Whenever I try to open the Level Editor I get this error message:

The code execution cannot proceed because SDL.dll was not found.
Reinstalling the program may fix this problem.  

If anybody knows how to fix this problem, please let me know, it will be much appreciated.