Click on Settings
Select Tags at the top of the page.
Select the Create New Tag button
Enter the name or the Tag, a Description and select a colour for the tag. Click on 'Save Tag'.
To Edit a Tag that has already been created, click on the pencil and make the required changes. Once all of the changes have been made click on 'Save Tag'.
To Delete/Archive a Tag that already exists, click on the red archive button under Actions.