Managing a category very straightforward, you have two options which are edit and archive.

Path: Space > Ellipse Icon > Settings > Categories

Select your desired space to see the Ellipse Icon.

Edit Category

To manage the category click the Ellipse Icon on the right of the category box and click on the Edit option to do the editing.

Now you can edit the category details then click the Submit button.

Archive Category

Next to archive the category click the archive option.

You can view the archive category by clicking the Filter button.

Path: Filter > Archive

Restore & Delete Category

For the archive category you can either restore or delete. To restore, click the restore option.

Next to delete, click on the delete option.