You do indeed have an array of hashes (or rather an array of hash references), and to loop through them is actually quite easy:

foreach my $var ( @{ $form->{PR} } ) {
    if ($var->{'id'} == $form->{'id'}) {
        print qq|elem->key $var->{id} eq $form->{"id"}\n|;
        print qq|\t\t cleared? $var->{cleared} $form->{"cleared"}\n|;
        if ( $var->{cleared} != $form->{"cleared"} ) {
            $var->{cleared} = $form->{"cleared"};
            print qq|\t\t FIXED $var->{cleared} $form->{"cleared"}\n|;
        }
    }
    else {
        print  qq|var id: $var->{id} ne form $form->{"id"}\n|;
    }
}
[download]

Output:

var id: 10368 ne form 12594
var id: 12585 ne form 12594
var id: 12592 ne form 12594
elem->key 12594 eq 12594
         cleared? 0 1
         FIXED 1 1
[download]