Follow the normal WordPress Plugin procedures - no special template tampering is required.
- Upload 'wp-digg-conditional.tar.gz' to your plugins folder.
- Uncompress the archive, preserving the folder structure.
- Activate the plug-in through the "Plugins" section of your dashboard.
- (Optional) Edit the $minDiggs variable in "check-digg-stats.php" to customize the number of Diggs are article needs to receive a badge.