Laravel Add a new column to existing table in a migration

I can't figure out how to add a new column to my existing database table using the Laravel framework. I tried to edit the migration file using... <!-- language: php --> <?php public function up() { Schema::create('users', function ($table) { $table->integer("paid"); }); } In terminal, I execute `php artisan migrate:install` and `migrate`. How do I add new columns?