Redirecting www to non-www?

[Mitchel]

First backup your .htaccess file.

If you use WordPress 3.8, you can change the site URL in General Setting, but you already know it :-D

It will be redirected automatically, no need to add any code in .htaccess

However if you already submitted your site in Google's webmaster tool, you need to edit "Site Settings" and "Set preferred domain" to use with www or without www.