Can't change WiFi username after entering incorrect credentials (Ubuntu 13.10)

Question

I have to enter a username and password to log into a new WiFi network. I entered the wrong username the first time I tried to connect. The username has been grayed out every time I've tried to connect after that:

WiFi usernames are stored in config files inside /etc/NetworkManager/system-connections/ but having to enter terminal commands to edit a config file in vi just to connect to WiFi is abstrusely convoluted to most people. It's one of those things that pushes a lot of people back to Windows. :(

Answer 1

Go to network settings:

and Click the arrow next to the network name:

then Click Forget Network

Answer 2

Alternatively (I am using 16.04 LTS), rather than forgetting the network, search for "passwords", click on "Passwords and keys". Under Passwords, Login, it should be listed as a Network secret for WIFI-NAME. You can double-click that and change the WIFI password in the dialog.

Note, although can edit wifi connections by clicking the Network icon in the status bar and then, Edit Connections, you can't change the password there, but you can using the above method.