To expand on what Valerie said, after removing the plastic piece covering the brush, take the top shell off the vacuum. Look on the bottom of the vacuum. You will see two snaps on each side. Take a long flat head screwdriver and insert it between the shell and the inside of the vacuum. Apply outward pressure and the shell will pop out of the snaps. Do this to all four snaps, lift up, then place the vacuum handle down and pull the shell off.
Thanks to Valerie and everybody else.
Tom, January 2013