Override \app\addons\paypal\payments\paypal.php

Is it possible to override this file with my_changes addon? If yes, please advise file path. Thank you.

No, you cannot override this file

Is it possible to override this file with my_changes addon? If yes, please advise file path. Thank you.

If you want to override this file, you need to create a new payment (full copy) with file for ex paypal_adv.php and change code u need.