Problem with the Rebranding Wordpress MU Plugin

OK, I am really really struggling with this plugin.

I have installed everything, and I have changed the images that it tells you to on this page: https://premium.wpmudev.org/project/rebranding-wordpress-mu

However, none of the images are changing!

This logo in particular is really annoying me, where is it located so that I can edit it!?!

Please help!

Gracias,

Damian.