Well, “simple” is a relative term, but there are a couple of ways to accomplish this, and you can find details regarding them at http://codex.wordpress.org/Moving_WordPress.
Note that if you installed this using the one-click installer an you do this you will “break” the installer’s ability to upgrade the site for you (it is not where it put it any longer), but as the newer versions of WordPress include the ability to upgrade from the WordPress dashboard this may not be of significant concern to you.
–rlparker
–DreamHost Tech Support