Treebuilder API is cancer. Use something better. 
use Web::Query::LibXML qw();
my $w = Web::Query->new_from_html(<<'HTML');
<body>
…
HTML
$w->find('blockquote p')->each(sub {
    my @parts = split ' ', $_->text;
    if (@parts > 1) {
        for my $p (reverse @parts) {
            $_->after("<p>$p</p>");
        }
        $_->remove;
    }
});
print $w->as_html;
__END__
… <blockquote id="two"><p>ddd</p><p>eee</p><p>fff</p></blockquote> …

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In reply to Re: Replacing an HTML element with multiple elements using HTML::TreeBuilder by daxim
in thread Replacing an HTML element with multiple elements using HTML::TreeBuilder by mldvx4

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