Help option in pause menu.

Hi everyone!
I want to make a help option in the pause menu to replace the save option.
I already got the first part down in the script editor

def main
    # コマンドウィンドウを作成
    s1 = $data_system.words.item
    s2 = $data_system.words.skill
    s3 = $data_system.words.equip
    s4 = "Status"
    s5 = "Help"(Replaced save)
    s6 = "Exit"
    @command_window = Window_Command.new(160, [s1, s2, s3, s4, s5, s6,])
    @command_window.index = @menu_index
    # パーティ人数が 0 人の場合

So what I did so far was just change the "save" to "help"
But what I need to know is where do I go from here? How do I actually make a command for help so it will replace the save function?

The only way to do that is to edit a big chunk of the script, your best bet would be to have to book that you obtain at the start of the game, call it something like "Book of Guidence" Then just have a common event for when it is used telling you... well.. help I guess!