Original Link: http://digwp.com/2010/02/remove-nofollow-attributes-from-post-content/

If you have posts that include the nofollow attribute on links, you may at some point decide to remove them. By default, WordPress doesn’t insert nofollow attributes in post content, but there are a variety of plugins that will insert nofollow into all links in post content. Or perhaps you have been manually adding nofollow tags to your post links for SEO purposes. Regardless of how they got there, it’s very easy to clean things up and remove all nofollow attributes from post content.