Thread:Mammon07/@comment-36590121-20191023202252/@comment-36590121-20191024171053

Go into "Edit" on any of the pages (in Source Editor). You should be able to click the little trash-can icon when you hover over the categories that the page is a part of.

I also highly suggest learning how to use the source editor, it's more powerful, cleaner, and not difficult to use, tbh.