The Microsoft Office 2013 DocRecrypt Tool allows admins to unprotect or change the password on password protected OOXML Word, Excel and PowerPoint files.

The tool gives admins who have configured the Escrow key feature options to get access to password protected files. The admin uses the tool and the private key of the escrow certificate to decrypt the file. Once decrypted the admin can choose between creating an unprotected copy of the file and changing the password of the file.

You can download it here.