Based on: The WordPress Rus filename translit plugin by fixed77. Russian filename and link (from title) translitter for WordPress.
To use plugin, you will need:
an installed and configured copy of WordPress version 2.6.x, 2.5.x, 2.3.x, 2.2.x, 2.1.x, 2.0.x, or 1.5.x. (WordPress Signaturer will also work with the equivalent versions of WordPress MU.)
FTP or SFTP access to your web host
Download plugin archive in zip or gzipped tar format and extract the files on your computer.
Copy plugin in the
directory of your WordPress installation. Use an FTP or SFTP client to
upload the contents of your archive to the new directory
that you just created on your web host.
Log in to the WordPress Dashboard and activate plugin.