Changing key in windows server 2012

When installing a new win 2012 OS in case where key is not installed immediately during install wizard you might get into issue where there is not place in GUI (at least that I could find) where you can change to appropriate key in order to activate windows.

Thanks to powershell there is even easier way of doing this:

slmgr -upk (this removes the current Product Key)
slmgr -ipk XXXX-XXXX-XXXX-XXXX (this installs the new Product Key)

Once key is installed using first command you can also go to action center in order to use GUI to enter key and activate windows.