That's a very good question.
I know as a fact, that first and foremost, I would make sure that I had all my business right with God.
I would then turn my energies toward loving God, my family, and neighbors like never before. What I mean when I say "like never before", is that it would be my sole occupation and obsession in life. I would also want to make peace with anyone that I have not fully forgiven and seek forgiveness from anyone that thinks I may have transgressed against them. This is no time for pride or playing games...this is my last chance to live well and die happy.
Lastly, I would make sure that my family does not feel more pain than is necessary, by making sure my estate is in order - all debts paid off and making sure my last will and testament is well written and thoughtfully considered, leaving nothing to the imagination.
I think I could die in peace and quite happy if I knew all these things were in order and all these things had been fulfilled.