Install Drupal Console Launcher using the phar

curl https://drupalconsole.com/installer -L -o drupal.phar
mv drupal.phar /usr/local/bin/drupal
chmod +x /usr/local/bin/drupal

NOTE: If you don't have curl you can try

php -r "readfile('https://drupalconsole.com/installer');" > drupal.phar

Update DrupalConsole Launcher

drupal self-update

drupal

You must execute the launcher within a drupal site directory or use --root=/path/to/drupal8.dev to specify your drupal site path.

NOTE: The name drupal is just an alias you can name it anything you like.