Q: I would like to change my Short Name. But no edit menu in the directory to choose root.

Like the title says, pretty self explanatory. I bought this MacBook from a friend of mine and her name is still on the Home Icon (short name). I get the idea of how to change it but once I get to the Directory Utility to enable the Root User, I find that there is NO edit menu. So now I'm somewhat at an impasse on how to do this so I've decided to come here for some help. Sorry if this has been asked a million times, I've gone through some other topics somewhat similar and nothing remotely came close to this issue. I find it odd that I don't have an Edit Menu in the DU. If there is a different way to this then please let me know, if not then please walk me through this. Thanks!