How can I remove the explicit label from a song? I bought a song from iTunes that is marked as explicit. However, the song is not actually explicit. When I try to edit the song's info in iTunes Music Library.xml, it simply reverts to the original information upon opening iTunes. Is there any way to remove the explicit label? 

Edit: I would prefer to do this without any third party software, but it doesn't matter too much.
Remove rating for one song
The app subler allows to edit a song's info manually. I've successfully tried version 0.14 in Lion.


Remove (suppress) ratings for all songs
You can choose to not show explicit labels for all songs in the parental controls of iTunes: iTunes Preferences -&gt; Parental -&gt; Show content ratings in library