my %hash = (
             '103496-1'  => [{ 'CLVD' => '5678', 'COMP' => '1234', 'FD' => '0010', 'Files' => [{'File' => 'text.txt', 'hash' => 'a538346ad3485'},{'File' => 'text2.txt', 'hash' => '237d97892376a'}] }]
           );

print Dumper(%hash);
print "\n";

my %newhash;
my $fn;

foreach $fn (values %hash) {
        $newhash{$fn->{COMP}}= $fn;
        delete $fn->{COMP};
}


print Dumper(%newhash);
print "\n";