[sudoers] Exit/save edit to sudoers file? Putty SSH

To make changes to sudo from putty/bash:

• Type visudo and press enter.
• Navigate to the place you wish to edit using the up and down arrow keys.
• Press insert to go into editing mode.
• Make your changes - for example: user ALL=(ALL) ALL.
• Note - it matters whether you use tabs or spaces when making changes.
• Once your changes are done press esc to exit editing mode.
• Now type :wq to save and press enter.
• You should now be back at bash.
• Now you can press ctrl + D to exit the session if you wish.