How to add my companys logo?

I want to display my companys logo for all customer-accounts, today there is a “User Logo” at the upper left.
Looking at siteworx/siteworx.php in a browser I can see where to add the logo - but opening that file in an editor doesn’t work. (Copyprotection or what?)
So how do I add my logo?

Pingu, you need to take a look at:

This explains how the template system works. There’s no easy “uploadyourlogo” option.

Regards
-tsl-