how to change enum values in migration files in laravel code example

Example 1: laravel enum migration

Add Laravel enmu migration : 
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$table->enum('question_type', ['objective', 'subjective', 'multiple_choice']);

Update Laravel enum migration :
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DB::statement("ALTER TABLE users CHANGE COLUMN permissions permissions ENUM('admin', 'user', 'candidate') NOT NULL DEFAULT 'user'");

Example 2: Laravel Migration - Update Enum Options

DB::statement("ALTER TABLE users CHANGE COLUMN permissions permissions ENUM('admin', 'user', 'candidate') NOT NULL DEFAULT 'user'");