You must have full administrative permissions in your space to perform these steps.
The KB is currently in the process of moving to a new WYSIWYG editor. As we transition, there are currently two editors to choose from within the KB.
For your own group space, you may prefer to use only the newest editor (TinyMCE), or to allow authors to switch between TinyMCE and the Classic editor. The option to set which editor(s) are enabled for your group space is described below.