User blog comment:Rafe62/Whassup people?/@comment-4909238-20120422082345

Removing categories:

When you press "Edit", on the right should be things to insert pictures etc. There's one part that says "Categories". If you scroll over one, near the edge, a bin icon appears, which is the remove button. If you press that, it removes that category.

As for re-naming, only Admins can do that.