I couldn’t find any information on the internet around this information, so when I received some information from a Microsoft buddy, I would I’d share.
VmmadminUI /Connect: “[server],[port],[user role],[use current creds (true/false)]”
Note that the quotes are mandatory. User role and use creds are optional. Use “da” for the role if you want to log on as the built-in administrator role:
.\VmmAdminUI.exe /Connect: “vmm2012r2a,8100,da”
.\VmmAdminUI.exe /Connect: “vmm2012r2a,8100″
If you get in to a bind, you can also specify /specifynewserver to reset:
Hope this helps.