How to clean up multiple Drush Composer installs? I've been setting up a new Ubuntu 16.04 laptop for Drupal development. I had trouble installing Drush using Composer, but eventually got things working. Today, while setting up Drush tab completion, I discovered five instances of drush.complete.sh:

$ locate drush.complete.sh
/home/monkey/.composer/global/drush/drush/vendor/drush/drush/drush.complete.sh
/home/monkey/.composer/vendor/bin/drush.complete.sh
/home/monkey/.composer/vendor/drush/drush/drush.complete.sh
/home/monkey/.config/composer/vendor/bin/drush.complete.sh
/home/monkey/.config/composer/vendor/drush/drush/drush.complete.sh

*cough* I think I need to clean things up and start from scratch. How can I correctly uninstall all these Drush instances?
composer global remove drush/drush will get rid of either the ~/.composer or the ~/.config copy, depending on your current configuration.  However, if you are no longer using the components that you installed via composer global, you can just use rm -rf to delete the directories you don't need, which is vendor and bin in ~/.composer and ~/.config.