iPod Deleting iPod Nano album art

I have an iPod nano and wanted to add album art to the songs that I loaded from CDs. I got a pic and inserted it onto my iPod and it worked. But when I went to add another pic, I put it on the wrong album, and now I have a huge Kelly Clarkson pic on my Michael Jackson songs. I tried placing the right pic over the original, but it didnt work. Does anyone know how to delete the album art??? I really hope so!!!!!!!
THANX