The given version is described here: How do I rename a project in Xcode 5?
But, as you can see from the following screenshot^, not everything gets renamed, and if one opens package contents, directory names etc. to try to manually change all the references, the project is broken afterwards, so you have to keep the old project name for sub directories etc., which granted is not a massive problem, but is intensely irritating, and I'm not enjoying being intensely irritated at work.
^ apologies for a screenshot, but there's too much information in it to transcribe to written text. Top two-thirds of screenshot is XCode project, bottom third a Finder window.