Ain't Nothing But a Thing
You have to pull the skewer out at least far enough to clear the wheel. Personally, I like to pull it all the way out and let the derailleur and hanger flop around on the end of the cable. It really trips roadies out. To make things easy, I flip the bike upside down, so it rests on the seat back and the handlebars. Once you've done it a few times, it's a snap.
Mark