Connect to the Beaglebone from your host computer (see Setting up Headless Operation).
Type uname -a to determine your OS version. When you look for beaglebone tips on the internet, be aware that there are huge differences based on kernel. This blog is based on 4.19.94 kernel.
Set the root password with sudo su (use temppwd as the password). Type passwd and enter the desired root password twice.
Switch directories to /etc/ssh, and edit sshd_config with nano (sudo nano sshd_config). Change the line “PermitRootLogin prohibit-password” to “PermitRootLogin yes” and restart sshd with “service ssh restart.” This will allow you to ssh into the box as root using the new root password.