1. Composer 설치하기
Composer dependency manager | PhpStorm Documentation (jetbrains.com)
> Preferences | PHP | Composer
2. 본격적으로 rector 설치하기
Rector | PhpStorm Documentation (jetbrains.com)
참조
https://durumis.com/ko/@xperiqabc9c8fd3/introducing-the-php-version-upgrade-tool-rector-rtmhuijb