code?

is there any software that i can get to pull code from games so i
can modify them?

In a sense, yes... it goes two ways. First off, there's just decompilation...
http://www.itee.uq.edu.au/~csmweb/de...tion/home.html

Although really, you'd be better trying your luck with a hex editing program, like Hackman. Hex editing however takes an awful lot of time and know-how (and it's not really pulling code, but capitalizes on the fact that most of the usefull information in a game is not code).