How to change
username on elementary OS — e.g.
This has been answered in another question on another StackExchange site but this is basically what you need to do:
While the user you need to modify is logged out and you're logged in as another sudoer user, do the following:
sudo usermod -l newUsername oldUsername
This changes your username but not your home folder. If you're okay with having a different home folder name from your username, you're pretty much done. Otherwise, refer to the linked answer for more details.