There are 2 steps to change a primary domain in Plesk for VPS/ Dedicated Server Hosting
a) Renaming a domain via Plesk
Log in to Plesk.
Go to Domains > example.com > Hosting Settings.
In the Domain name field, change the domain name.
Apply the changes.
Note: If this is the main domain, subscription name will be also changed.
b) Renaming a domain via a command-line interface
Connect to a Plesk server via SSH (Linux) / RDP (Windows Server).
Use the 'plesk bin site' utility to rename a domain. In the example below, we are renaming example.com to example.net:
Note: On Windows Server, start a command prompt as an Administrator.
# plesk bin site --update example.com -new_name example.net