Follow these simple steps to change the hostname on a ubuntu machine:

Step 1: Update /etc/hostname file

This file contains the current hostname of the machine. Update the name to your

desired name.

$ sudo vi /etc/hostname

Step 2: Update /etc/hosts file

Replace the current hostname in the file with the desired name.

$ sudo vi /etc/hosts

Step 3: Set the hostname using the hostnamectl command

$ sudo hostnamectl set-hostname new_hostname