I've looked through tags and found this and this entry that closely match what I want to do, but the first one doesn't include a solution and the second one begins at a place too advanced for me. I have a mixit theme with a custom layout and want to call my sidebars different things than the default. I've read this from lj, but I don't know 1) where I'm supposed to type the code once I get into my layer to edit or 2) what code I'm supposed to write.
I've also read this, but it shows how to build a new theme, not edit an existing one as far as I can understand.
Am I being clear about what I want to know? The edits I want to happen are at the level of the theme, I know, not on the custom css level, but what code to write and where to write it once I'm at 'your layers' in Advanced Customisation and I find this - [15739992 theme (none)] - and I click the 'edit' button are my questions.
Thanks in advance.