Forum:How do I customise my Wikia Community Logo?

Hi,

I've been to this link: http://www.wikia.com/wiki/Help:Improving_your_Wikia#Change_the_logo and i still can't figure out how to upload my own logo for my wikia community. I changed the filename to Wiki.png but this is protected, and just uploading the image as a JPG but that doesn't seem to implement any changes.

so... Help?!

Thanks!