Thread:EvergreenFir/@comment-24616208-20140222140520/@comment-4904721-20140223222924

Here's an image of where the categories are listed in Source Mode: http://imgur.com/MPO6tfV

You need to hover your mouse cursor over the category name for the little trash can (delete) and pencil (edit) icons to appear.

Some categories are transcluded with templates (i.e., they are automatically added by templates). You can only remove categories not added by templates.