Quoted directly by Aaron from:
“This guide will give you the steps needed to reset the license file so that you can apply the evaluation license back to your ESXi host.
WARNING: This is for education/informational testing/development purposes only, and should not be used on a production server.
To reset your expired ESX 4.x, ESXi 4.x, ESXi 5.x or ESXi 6.x 60 day evaluation license:
- Login to the HOST via SSH or Shell
- Remove /etc/vmware/license.cfg
- Copy /etc/vmware/.#license.cfg to /etc/vmware/license.cfg
- Restart the vpxa service
Or simply copy the code below and paste it into your SSH session.
rm -r /etc/vmware/license.cfg
cp /etc/vmware/.#license.cfg /etc/vmware/license.cfg
Then open the “Licensed Features” option in the configuration tab of the ESXi host through the vSphere Client.
Click on “Edit” in the top right of the “Licensed Features” page
Once the “Assign License” window opens you will see two options. There will be a category for “Evaluation Mode” and Assigned License. Click on the “(No License Key)” option and then click “OK”. This will set the host back to “evaluation” mode and will give you access to all features for 60-days!”