Is there a place I should look, or can someone tell me, how to change the clock format from 24 hr to 12 hour? or is this something that is theme-specific.
From what I can tell, the theme I have is "YF19."
I also freeze when I try to use the app to change themes. I have to kill the process with task manager.
Thanks in advance

Try the docs. The docs for LSXCommand have them, Popup docs used to, but they've had a good reworking. If you know what module displays the clock, try those docs.

About the broken theme changer, use Omar's LS Installer instead of EZ2Install.