How to voice the game?

I have a great voice and diction. I do some game reviews and is pretty popular as Vkontakte obzorschik. But recently I came up with a new idea. I decided to name the game.
We are talking about the game Silent Hill 3, although this is not essential. I want to know is it even possible to voice the game at home? That is, what do I need? Some program or what? After all the sound files in the game folder in some obscure format... is There any Converter to recode these files to wave for example? And there shouldn't be any problem to voice the game))