From the homepage, look for the RUSH 24/7 MEMBERS ONLY box on the right side of the screen and log in. Once you are logged in, under the photo of Rush sitting in the studio, you will see a link for the Podcast Center. This page features all available audio for the past 30 days, ready to download.
You will see a listing of the dates of the shows. Find the date you want, and each hour that you want for that date.
PC USERS need to right click and "Save Target As..."
MAC USERS need to ctrl+click and "Download Link to Disk."
You can find more information on podcasting the show in iTunes HERE.