How to make up for disobedience towards parents after they have died

If a person was disobedient towards his parents, and they died angry with him, how can he put things right so that they will not ask him to put it right in the Hereafter?

Praise be to Allaah.

There is no way to stop them asking him to put things right in the Hereafter, but now that he has felt regret for what he did, he should make lots of du;aa; for them and ask Allaah to forgive them, give charity on their behalf if he can, honour the friends etc, whom they loved, uphold their ties of kinship, pay off their debts and do whatever else he can.