Consolidating the steps for readers:
ssh to the cmx with Management IP and credentials of cmxadmin
Type "su"
Type "passwd <username>".
It will ask for the existing password of the user specfiied followed by prompting the new password that you would like to set.
The same way other users passwords can be set.
The users that are configured on the cmx can be obtained by issuing the cli "cmxctl users list"
