Change text covered by a motion with c{motion}. Vim deletes the target and drops you into Insert mode.
Commands you practise
c{motion}
Change text from the cursor up to a motion and switch to Insert mode. Combining change with till (t) or find (f) makes quick edits surgical.
Levels
String Theory (easy): Change the message inside the quotes to greet the galaxy.
Clean Arguments (medium): Replace all function parameters with a single config object.
Double Till (hard): Replace the age and role with a single title using a count-based motion.
Each level opens a real Neovim session in your browser with a start file and a target file. Edit one into the other in as few keystrokes as you can, then race the vimbot's solution.
Part of VimGolf.ai Premium ($10 once, lifetime). Region: change and substitute (operator). See the whole skill map.