Ckeditor button customization

I’m following the ‘Put Dedicated Insert Macro Buttons on the Tool Bar’ section on the following ckeditor page:

The actual macro button insertion works fine. However I am a loss as to where I should be adding the additional css so the button is more than just a blank square. The instructions simply state: “Then, you can control the button icon from the skin”.

Should I be manually editing the …/webjars/wiki%3Axwiki/application-ckeditor-webjar/1.13/skins/moono-lisa/editor.css file on my server or is there a place in the xwiki UI to make the addition ?

Hi, I’ve updated with more information and links (I recommend you try using a SSX, it’s the simplest I think).