Unless you have a backup, this could be tough going. It uses unbreakable encryption to this point. The malware can be removed but files are likely unrecoverable. However, see this article by Mick2009 to see if it can help:
Recovering Ransomlocked Files Using Built-In Windows Tools
https://www-secure.symantec.com/connect/articles/recovering-ransomlocked-files-using-built-windows-tools
Multiple links here as well:
https://www-secure.symantec.com/connect/forums/cryptolocker-qa-menace-year
Similar problem to yours here:
https://www-secure.symantec.com/connect/forums/some-virus-has-corrupted-many-our-microsoft-office-files-and-pdf-files
How to run Symantec Power Eraser with the SymHelp utility
http://www.symantec.com/docs/TECH203683