How do you change the default passwords for xmsadmin and xinstall?

I have read the doc.

https://support.emc.com/docu71061_XtremIO-XIOS--4.0.2-and-4.0.4-and-4.0.10-and-4.0.15-and-4.0.25-with-XMS--4.2.0-and-4.2.1-and-4.2.2-Storage-Array-Security-Configuration-Guide.pdf?language=en_US

And this support article.

https://emcservice.force.com/CustomersPartners/kA2j0000000QXG5CAO

The support article doesn't address how to change passwords for xmsadmin and xinstall.