What you do is click profile at the top bar next to where it says messages and all of that stuff then when you click that there will be another bar a little bit down starting with the word information, then what you want to do is look for the word signature on the line click it then go down to the box that looks like the box we used to reply in threads.
type in [*img]put the link to your signature here[*/img]
You don't put the " * " in that is just so the site doesn't think im posting a picture.