G'day all..
One post mate, that's all you need.
And in answer to your question, I'm not terribly sure because ive never wanted to change controls (play with A + Z and < + >, once you get used to it it's the best way you can play.) but I'd try first making the left arrow key a button that isn't in use, which then frees up the left arrow key...see where I'm going? You could do that for all buttons. I'm not sure if this would work or not, but you can try. Also, someone here might be able to give u a wayyy easier solution, like an *ini file or something, I don't know.