Thread:Tr143/@comment-26899251-20160709170758/@comment-26190625-20160709171912

Go to edit, Classic Editor, then, on a right side, you should see that there's a  column named "Category", click on it, it will show you all the current categories on that article, then simply "move" your mouse over to the one you want to delete, then you'll see that at the very end of it has a "trash can/Recycle Bin" symbol. Click on it and you'll be able to delete it..