Look for college/university courses in writing. Perhaps set up your own games review website/blog, or find another that you can contribute to. Then send out job applications to every game review magazine you can find.
Also I'd recommend you practice researching information, as that's likely to be something you'd have to do if you got a job as a reviewer. In the "Writing" section of the forum on the first page, if you do a quick scan you'll see the following threads that are likely to have useful answers:
Advice for a newspaper journalist
What can I do to break into the industry as a journalist?
looking for game journalist jobs
Could I cut it as a game journalist?