well, the "icons" are actually images that omar included with the theme. to "change" them, you would actually need to make new icons yourself, or find the ones you want on the net somewhere. now, to change where they point to, the target's are specified in one of simplicity's config files. as I don't have simplicity on my system right now (though with all the problems people are suddenly having with it, maybe I SHOULD download it), I can't point you to the specific config file.