You normally enter all scoring commands from the summary buffer, but you might feel the urge to edit them by hand as well, so we've supplied you with a mode for that.
It's simply a slightly customized
emacs-lisp mode, with these
gnus-score-edit-insert-date). This is really the day number, if you were wondering.
gnus-score-pretty-print) does that for you.
Type M-x gnus-score-mode to use this mode.
gnus-score-menu-hook is run in score mode buffers.
In the summary buffer you can use commands like V f, V e and V t to begin editing score files.