A step-by-step on changing the VMWare ESXi v.6.5 & v6.7 hostname
1. Login to the Web Client interface.
2. Browse to the Networking menu.
3. Select Default TCP/IP Stack
4. At the Actions button, select Edit settings.
5. Click on Manually configure the settings for this TCP/IP stack
Edit the [Host name], [Domain name] and any other settings you’ve wanted.
6. Once completed, click the Save button.