drop foreign key laravel

//...
class ClearOldOauthRelations extends Migration
{
    public function up()
    {
        Schema::disableForeignKeyConstraints();
        // drop foreign keys
        Schema::table('oauth_access_tokens', function (BluePrint $table) {
            $table->dropForeign('oauth_access_tokens_session_id_foreign');
        });
        //...
        Schema::enableForeignKeyConstraints();
    }
    //...
}

Schema::table('table_name', function (Blueprint $table) {
    $table->dropForeign(['foreign_key']);
    $table->dropColumn('column_key');
});

PS: usually foreign_key = column_key

ex: 

Schema::table('despatch_discrepancies', function (Blueprint $table) {
    $table->dropForeign(['pick_detail_id']);
    $table->dropColumn('pick_detail_id');
});

Schema::table('admins', function (Blueprint $table) {    $table->dropForeign('admins_post_id_foreign');    $table->dropColumn('post_id');});