Unfortunately, you can not change the URL, but you can change the title of your hub. When in edit mode you just need to type in the title you want to change it to.
However, if you're determined to have that URL, you can see if it is available. If it is, you can copy and paste your already published hub into the new one. Once it is published you can unpublish and delete the old one The downside is that you will lose the views & stats you've got on the old hub.