Find another rule
Privatization

PrivatizeFinalClassMethodRector

Change protected class method to private if possible

 final class SomeClass
 {
-    protected function someMethod()
+    private function someMethod()
     {
     }
 }

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\Privatization\Rector\ClassMethod\PrivatizeFinalClassMethodRector;

return RectorConfig::configure()
    ->withRules([
        PrivatizeFinalClassMethodRector::class,
    ]);

Other rules in the Privatization set