First on Profile

Scroll down to the Avatar Control Panel. Click on the 'Browse' Button

Choose whatever image you want to upload . Its width can be no greater than 128 pixels, the height no greater than 128 pixels, and the file size no more than 49 KB.
(If you don't know how to edit pictures, web sites like http://www.shrinkpictures.com/ have tools to help you out)

Click Submit

Picture will up uploaded to the Scooterdiva server.

Click on Profile again and scroll down and you should see your image.