Simply Remove Special Characters from WordPress attachments, slugs and permalinks. This plugin allows you to remove all special characters from WordPress attachments without modifying the code and it works with most of the available themes. Just install and activate this plugin to remove special characters from post and pages in WordPress.
Read more about this plugin on WordPress blog.
Dieses Plugin steht zum Download zur Verfügung, um in deiner selbst gehosteten WordPress-Installation verwendet zu werden.