Plone 4.2 - how can I change the logo in a diazo t

I have just installed a theme in Plone called beyondskins.responsive. Now I want to change the logo so that it uses the logo for my site and not the default Plone logo. I've spent an hour googling this problem and I have not found a solution.

One of the places I looked was here: http://pypi.python.org/pypi/plone.app.theming#modifying-the-theme This site tells me "You can modify a theme by clicking Modify theme underneath a theme in the Themes tab of the Theming control panel." However, I don't know how to find the "Theming control panel" that they are speaking of. When I go to "Site Setup" after logging in as admin I see an option called "Diazo theme" and another option called "Themes" (just the fact that there are two annoys me...) but neither of these options has a "Modify theme" option.

Another place I looked was here: http://quintagroup.com/services/support/tutorials/index_html#plone-visual-design These guys have separate tutorials for each of about 30 different themes (one tutorial for customizing the Estate theme, another tutorial for customizing the Estate Classic theme, another tutorial for customizing the Coral theme, and so on...) The theme I am interested isn't listed, but all the tutorials seem to be similar and the first thing they address is how to change the logo. For instance, here are the instructions for changing the SkyCream theme logo: http://quintagroup.com/services/support/tutorials/skycream/diazo/logo

They tell me: "You can replace this logo with yours via ZMI. Open portal_skins -> sunburst_images folder, there is logo.png image. To set your own logo press Customize button." However, my system, which is running Plone 4.2 does not have a Customize button at this location. Perhaps these tutorials are aimed at Plone 4.1.

I'm starting to feel like I could have written my own theme from scratch faster than figuring out how Plone works. Please help.

UPDATE: Ok, so if I go to: mysite:8080/manage_main I get a list of the stuff at the Zope root. From there I click on my Plone site. From there I click on "Portal Skins". From there I click on "Sunburst Images". I then see a page with links to logo.png and pb_close.png. I then click on "logo.png". At the bottom of that page there is a button called "Customize". I click on it and it takes me to a page with the title "Image at /myplonesite/portal_skins/custom/logo.png" and gives me an option to choose an image file to upload. So I upload the image file that I would like to use as my logo. I then click "Save Changes". Now, my image file is larger than the original Plone logo. So it shows a larger logo, my logo, on this page after I complete the upload. I then go to my site to see my new logo. What I see instead, however, is the original Plone logo, but this time it is blown up much bigger!!! So it didn't change to a new logo -- it just kept the same logo but used the sizing information for the bigger image. I would much prefer to just deal with the HTML/CSS directly as opposed to working through a GUI, but I can't figure out where the html/css files are stored for the theme -- they appear to be packaged in a .egg file.

I'm going to assume that the theme is using the static HTML file (as referenced by the rule in rules.xml) to place the logo, rather than pulling Plone's standard logo through using a rule. In this case, you simply edit the theme HTML file (usually theme.html or index.html) and/or replace the image file it references.

In other words: if you know how to do this with HTML and CSS, you know how to edit the theme.

As a side note: In Plone 4.3, we'll ship with an in-Plone theme editor that should make this even easier. You'll get an option to make a new, in-Plone editable copy of a theme with a rich HTML editor that you can use to modify the markup easily.