Managing header images in TwentyEleven theme??

Hey Guys, I have just upgraded to the TwentyEleven theme. I really like the rotating banners. I was hoping to just upload a bunch of images inot the directory and it would use them all. However I read here: http://www.technicalcommunicationcenter.com/2011/08/10/how-to-add-new-random-rotating-header-images-to-a-wordpress-ten-eleven-blog-theme/ that its not that easy at all. I see I have to add lots of code for each one.

My first guess is to simply upload my new images and rename them to the names that are already in there – would this work? Is there any easier way as I was planning on changing them very often!

P.S. I saw an addon plugin for TwentyEleven, is this any good or are there others I should consider to make it better?

Thanks 🙂