Dear Prologicam,
All you need to do is:
1) Click on the "Profile" icon on top of the page (underneath FAQ)
2) Scroll down to where it says "Signature" There you can type in any signature you want and if you want a picture you have to link it.
3) You link a picture by finding one on the web, right-clicking on it, chose "copy image location", then in the "Signature" box you put the IMG (image) code and paste the image location in between.
4) When you're down scroll down the page and click "Submit"
Try it and tell me if it works.
Ba Sepaas