Take a look at this instructional video and learn how to hack into your iPod's firmware on a Mac. In order to hack into the 5.5g iPod's firmware, you need to download the Alterpod, a firmware editing software. With this program, you'll be able to download themes onto your iPod. Keep in mind that this hack is for the 5.5 generation iPod and does not work for the 6th generation or the older ones before 5.5. When downloading themes, make sure to download the correct version.