Well, if you just finish your Nutanix implementation in your environment with AHV hypervisor or you just want to reset the password of all the Nutanix components here are quick steps to do

Reset Prism Password :- 

1. Access one of the CVM :- https://CVMorclsuteripaddresss:9440

Reset AHV HOST Password  :- 

1. Login to AHV host as root

If you do not remember password of the host. You can directly ssh to host from CVM without password

1. Execute the following command on the host:

$ passwd

Reset CVM SSH access password :-

1. Login to any one of the CVM servers as “nutanix”.
2. Type the command:

$ passwd

Changing password for user nutanix.

Changing password for nutanix.

(current) UNIX password

3. Type in the old password first and new password

Reset the IPMI User Password :-

1. Access the IPMI  webpage
2. select configuration
3. select the user and reset the password