You write a will. You state that you have a sister [Name] and that you are not leaving her anything. You say that your entire estate is left to [CharityName]. You name someone to handle your estate, typically called the executor.

Create a folder or binder that is clearly labelled “estate plan” or “last wishes” or “on my death”. Put that folder somewhere obvious, like in the front of file drawer. Put your will in it.

The executor pays any final bills, notifies heirs, and gets house ownership transferred or sells house and sends charity the proceeds.

Other things for your folder: Documents that will help your executor find your accounts like bank statement and voided check, 401k statement, electric bill, etc. Mine includes a list of people to notify of my death, a draft obituary, and a note about finding my passwords.

FYI, you need to name your closest relatives and specify that you are not giving them anything or are giving them a very small amount. Otherwise, they can challenge will on grounds that you forgot them.