Looks like you're there, except for how to edit /etc/config/luci
vi is available, but isn't "user friendly" http://web.mit.edu/merolish/Public/vi-ref.pdf is one of many cheat sheets that may be enough. If you get into trouble with vi, [ESC] should get you a colon (:) prompt at the bottom of the screen, from which q! means "quit and don't save"
nano is available as a package, which many find a little easier to use.