Renaming home folder

[appdev46]

As a test, I tried this whole process again.  I am pretty certain the wiki is wrong.

I downloaded the image from here:  https://github.com/mrfixit2001/debian_de...123.img.xz

I used Etcher to write the image to an SD Card.  
I booted and ran update script. 
I logged out of rock.
I logged into root
I opened the root terminal window and ran "usermod -l myNewUserName rock" and had no issues
I ran "usermod -d /home/rock -m myNewUserName"  and got the error -> usermod: no changes