What is it recommended for a sick person to do when his illness is terminal?

Al-Nawawi said: 

The sick person should strive to have a good attitude
and avoid arguing and disputing concerning worldly matters. He should
bear in mind that this is the end of his time in the realm of deeds,
and he should end it with good deeds. He should seek the forgiveness
of his wife, children, all his family, neighbours and friends, and all
those with whom he had dealings or with whom he was friends or had any
kind of connection, and ensure that they hold nothing against him. He
should focus on reading Qur’aan, reciting Dhikr, and reading stories
about the righteous and how they were at the time of death. He should
observe regular prayer and avoid impurity (najaasah), and take care
of other religious duties. He should not accept the advice of those
who try to turn him away from these things, for this is something with
which he will be tested, and this person who tries to do this is an
ignorant friend and a secret enemy. He should advise his family to bear
his loss with patience and not to wail over him or to weep excessively.
He should advise them not to do any of the bid’ahs (innovations) that
are customarily done at funerals. He should ask them to make du’aa’
for him. And Allaah is the Source of strength.