Chainging the link in header image

I have set up a multi-site network so that I can have multiple, separate blog pages for my site. I have had to mirror each blog to look like and link back to the original but I cannot figure out how to change the link in the header image so it links back to the original blog homepage rather than the new “features” blog homepage.

Is there a way to do this? I’ve been considering upgrading to the premium theme but this would be a deal beaker.

Thanks for any help!