Change top left logo

I switched to the Learn2 theme from the Learn2Git theme (or something like that) because it was outdated, and not maintained, at least I don’t think. Now at the top of my site on the left side, it reads GRAV. While I don’t mind the link in the footer, that is not what I want in the top left of my website. I tried the usual, setting the site title in the configuration of the site, and it refuses to load. I do not want to modify the theme, but am willing to do so if that is the only way… the problem is with updates, I then have to modify it again to keep the change. Any ideas on where to find or modify this?