How do I convert the Z420 from tower to desktop configuration?

Remove the front bezel, rotate the optical drive bay filler panel 90 degrees to horizontal, align the slots with tabs and snap it back in place, rotate the HP logo 90 degrees counterclockwise, remove and rotate the EMI filler panels and optical disk drive 90 degrees, then reinstall them and replace the front bezel and side access panel. A video of this task is available at http://www.hp.com/go/sml. (Page 23-24)