Maybe I'm doing it wrong, but the Xterm vi doesn't really seem that complicated for minor edits.

After launching "vi [file name]", I guess you start off in command mode. The D-pad moves the cursor, x deletes characters. Press "i" for insert mode where you can type whatever text you want to insert into the original file. Esc returns to command mode where you can use ":wq" to save and quit if you're confident that you did everything right, or ":q!" to quit without saving if you're afraid your messed something up.

I'm sure there's way more to it, but the above commands work for my minor modifications.