$foo = { 'SOMETHING_01' => {
                             'CLASS' => [
                                          {
                                            'VALUE' => 'BUBBLE'
                                          }
                                        ],
                           }
       }

##</code><code>##

my $fee;
%{$fee->{'SOMETHING_02'}} = %{$foo->{'SOMETHING_01'}};
$fee->{'SOMETHING_02'}{CLASS}[0]{VALUE} = 'SQUEEK';