Board Thread:General Discussion/@comment-5411479-20150928094312/@comment-1038387-20150928094644

Edit the page, look to the right hand side of the edit window. See if there's a menu there. If there isn't, look for a small arrow half way through and click it.

In that menu, look at the categories module. Hover over the category (towards the right end) and you'll see a trashcan appear. Click it. Save the page. Category gone.