default HDP stack selection

[Satyanarayana Jampa]

Hi,
                I am using "apache-ambari-2.2.2" and during install at Step1 
shows list of HDP versions and the stack Repositories:
                                The stack versions show:

?  HDP 2.2

?  HDP 2.3

?  HDP 2.4
                                And 2.3 is selected by default.
                                How can I change the default selection to 2.4.

                Also, in the Repository section:
                I would like to uncheck all others except Redhat6 and  change 
its URL.

                Please let me know the right place to change these values. So 
that I can change the code and rebuild.

Thanks,
Satya.