Wordpress nofollow links?

[thecableguy]

Anybody know how to change a self hosted Wordpress blog links from dofollow to nofollow?

I've tried to modify the index.php and single.php files replacing "<a href" with "<a rel='nofollow' href" but it seems to change some of the links, but not all.

I'm trying to change the external links to no follow. Is it possible to make some links dofollow and some nofollow?

Is there a plugin to do this or can it be done from within Wordpress?

Thanks

Alan