Reset VMware ESXi root password
If you forgot your vSphere ESXi * / 6 host root password, the only supported option by VMware for recovery is a new installation of the host.
Additional Information in the VMware Knowledge Base Article
How you can still reset the root password without a new installation , we will show you in this article.
However, we would like to emphasize that this approach may be neither be supported by VMware still by Thomas-Krenn.
You must boot a linux live system, or an installed linux system on another disc, on the vSphere Host. In our example, an installed Ubuntu 14.04 was used , the vSphere installation was on an USB stick .
Author: Sebastian Köbke