well ok first you right click the image of the sig and go down to save as
Then you go the top of the site, and hit profile, once tht is done you hit options I believe and you should see a big rectangle. Right below that is a clickable button, hit that. It should take you to an upload screen where you upload the sig. Once you get that far, a URl should come up, you right click, copy it, hit back a couple times til you see that open rectangle and hit paste, scroll to the bottom of the page and hit update