my $MSAD_HOST = "AD domain controller";
my $MSAD_DOMAIN = "AD domain"

Authen::Krb5::init_context() or die $@;
  
my $krb5conf = Authen::Krb5::Admin::Config->new();
$krb5conf->admin_server($MSAD_HOST);
$krb5conf->realm($MSAD_DOMAIN);

my $kadm5 = Authen::Krb5::Admin->init_with_password($user,
     $oldpw,
     KADM5_CHANGEPW_SERVICE,
     $krb5conf) or die $@;