It's just git reset --hard. HEAD is implied.

Edit: To be more specific:

    git  # the executable
    reset  # the operation
    --hard # the type of reset being done (hard reset)
    HEAD  # where to reset *to*. Defaults to HEAD if not specified.

You can just leave out HEAD since it is implied, but understanding a little bit about git, like what the head is supposed to be, would probably help you.

For rare commands that are repeated every so often history search comes in handy.