Would you be talking about the GameMe signatures? If so head over to " https://prestigegaming.gameme.com/playerinfo " and search for your Username or Steam ID. Select your user and you should see a boxed section named "Forum Signature" with the BBCode below.
You can either choose the default signature or click on "Preview all signatures" and choose one more to your liking. From there copy the BBCode and as Simon has previously stated head over to " https://www.edge-gamers.com/forums/profile.php?do=editsignature " and simply paste it into the textbox and save.