Board Thread:Support Requests - Getting Technical/@comment-24652145-20181031234617/@comment-9605025-20181101002713

Anything you can add/edit/remove in VisualEditor you can add/edit/remove in the rich-text editor; anything you can add/edit/remove in the rich-text editor you can add/edit/remove in the source mode editor. In other words, there is a way to do it, you just need to know how.

In the case of removing categories, open the the side bar if it is collapsed. Then, expand the categories section if it is collapsed. To remove a category, hover to the right of it and click the trash can icon. To add a category, type it into the text box at the top of the categories section. Depending on your personal settings, it will make suggestions as you type. For more information, read Help:Categories.

What else do you need to do?