Change theme name?

So I downloaded this plugin called “Theme Switcher” by Ryan Boren. It works pretty great at allowing users to switch between themes. I just added a new one to my site, and it’s been a partial hit. 50% like the old one better, 50% like the new one. So I decided to give them a choice.

The plugin gives a drop down for them to pick the theme (works fantastic).

The only problem is, the theme names are pretty archaic because it’s the actual name of the theme. I’d like to be able to rename it so that it says something simple like “Old Theme” and “New Theme”. Anyone have an idea how to set the name of the theme?

Seems like it would be pretty trivial, but I can’t figure it out.