Add a new user, with sudo permissions

1. copy your current root@ ssh key pair some place safe.
2. generate a new key par for your non-root user with ssh-keygen - (keep it to a different place to your root keys).
3. create another user on your droplet call him mrwww.
4. You'll need a way for your new user to become root. sudo or doas are god for this.
   • as root grant your new user access with echo 'mrwww ALL=(ALL) ALL' >> /etc/sudoers
5. copy the .pub from the new key pair into ~mrwww/.ssh/authorized_keys, and chmod 0400 it.
6. test your key will let you in with
   • ssh -i /path/to/new-id_rsa mrwww@yourdroplet
7. test that you can do stuff as root
   • sudo touch /tmp/what
   • ls -l /tmp/what # this should show the file created by root.

Hi, thanks for answering, but it seems your guide is to create new user, what I want is changing the name after @ on SSH command line, from root@my-initial-droplet-name to root@new-droplet-name.

Changing droplet name doesn't change this SSH address. I already deleted the login detail on my winscp and recreate it, but doesn't change anything either. Thanks

For most distros you will use hostnamectl on the command line.

https://www.freedesktop.org/software/systemd/man/hostnamectl.html

http://manpages.ubuntu.com/manpages/xenial/man1/hostnamectl.1.html