Unable to change administrator@vsphere.local password ( I forgot )

Hello All,

    can anyone help me to change the password of administrator@vsphere.local on my test infra.

I forgot the password which I given for this administrator@vsphere.local. please find the attached screenshots.

Vcenter Server version : 5.5

Windows OS Version : Win Server 2012 R2 Std and under workgroup.

Image may be NSFW.
Clik here to view.

Image may be NSFW.
Clik here to view.