this is what I did and it worked.
I'm using GoDaddy also
I renamed the logo that I wanted to use to YAFlogo.jpg
opened my GoDaddy account
went to the file directory
using the folders on the left side of the screen opened the one for YAF/images
uploaded the newly renamed file (YAFlogo.jpg) to the directory
it'll say that it exists, I checked the overwrite box