How often do you make apologies? And how often should you have made an apology? And if you make an apology do you really mean it?
Understand there will be no Trust in any relationship without Integrity. Consequently without Trust in a relationship there is no respect and understanding.
If the person who you would like to apologize has passed away you can still make it up to that person. How? By serving others. Assist others as everything is connected. Your own intuition will tell you when your 'karmic debt' is paid.