nopCommerce is the first 2.x version I have worked on, having worked all sites to this point in 1.8 or 1.9. The new installation was created using the "No Source Code" version.
After logging into code side of the site (with Visual Studio 2010) I could only find the Dark Orange and nopClassic themes. I've consulted the Users Manual which only reads that "you can also develop your own themes if you have a designer". Any web search yields the correct way to add a theme or edit the .ascx files for 1.x, but there are no .ascx files that I can edit as far as I can tell.
How do I install a new theme and where can I edit the current theme's layout?