post_install() {
  cat <<'MSG'

  bottles-opener is installed but not active yet.

    bottles-opener          interactive menu
    bottles-opener enable   set up file opening for your bottles

  Run it as your own user, not with sudo: it only ever writes inside your own
  home directory.

MSG
}

pre_remove() {
  # The changes live in each user's home and cannot be undone from a root-run
  # hook, so say so while the command that does it still exists.
  cat <<'MSG'

  Before removing this package, run

    bottles-opener disable

  as each user that enabled it. That removes the file types, launchers and
  icons it added and puts back the previous default applications.

MSG
}