Hard Time Changing Local Account Name

My two sign in options (Accounts) Not signed in to a Microsoft Account
Dave (Admin)
Local User: D.Leonard Admin Local User)

I want to change the D.Leonard Admin because it is a local user account, not Admin.
I have tried several different ways like the Control Panel but found no option to change the name. Next I tried the netplwiz in run but I was denied that option. So, I went into the terminal and ran the Rename-LocalUser -name "Dave Local" -NewName "Leonard". I was denied access to that.
So, I am having a lot of trouble changing the local username. Thanks.

 

Yes I did use the Admin for the terminal.
The control Panel option does not work. See the attachments. No option to change the name even as Admin or change account of another user. I guess my only option is to leave it like it is.

 

Did you run the terminal as administrator?
I was wrong, I was using the local account when running the terminal, So, I went back and ran the terminal as Admin and this time the system could not find the local account. See attachments. Is it possible that I need to change the name by logging into my Mocrosoft Account?

 

I figured it out. You have to go into the Microsoft site and log in to change name on admin or user or email. Can't do it from the pc. Microsoft is so controlling, it gets on my nerves sometimes. I put a couple of files to show the changes. The cyborg is my Admin account and the goofy D. Leonard is my local. Thanks.