The following list of functions will allow you to change text, cancel updates or repeat edits:

TIP: These commands (except for r) will put you in insert mode until you press escape:

Command What It Does
~ Change case of letter(upper or lower)at cursor
:u Undo previous last-line command
8cw Change 8 words
cw Change word (or part of word) at the cursor location to the end of the word
C Change from cursor to end of line
i(return) Break line
J Join current line and line below
r Replace character at cursor with one other character
R Overwrite or replace characters on line
s Substitute string for character
u Undo previous commands
U Undo all changes to current line
xp Transpose character at cursor and character to the right