Drupal - How do I uninstall Drush?

It seems there is no single remove command, so you need to:

1. Edit your composer.json file, e.g.

   vim ~/.composer/composer.json
   

   and remove line containing drush. Save the file.

2. Update Composer PHP packages by:

   composer global update
   

   It will remove a globally installed drush.

If you don't have composer command in your PATH, try php composer.phar instead.

See: How to remove a package from composer?.

You can use composer global remove drush/drush to uninstall a global Drush.

Or use composer remove drush/drush to uninstall a project-local Drush.