The following method is a way to add a new logo to your page with just CSS. If you wanted to make this more global you will need to use an alternate method to override the default CSS classes.
- Upload your new logo to either the server or to a list on your site.
- Add a Content Editor webpart to the page.
- Add in the following to the source viewer.
background-position: top left;
- In the example above I have uploaded the xyzcorp.gif logo to the images folder on the server.
- Make sure you modify the elements above in bold green: logo name, height, and width (of logo).
- Save the page and you should now have the new logo on the page.