Open your Settings. Choose Security and the Legacy Contact at the bottom of the page.
After choosing your legacy contact, you’ll have the option to send a message to that person.
You may give your legacy contact permission to download an archive of the posts, photos and profile info you’ve shared on Facebook.
Facebook has also redesigned memorialized profiles to pay tribute to the deceased by adding “Remembering” above their name and making it possible for their legacy contact to pin a post to the top of their Timeline.