my $test = Test->new(123);
$test->change(345);
print $test->{id}; # Should print 345

package Test;
sub new {
	bless{
		id=>$_[1],
	}
}

sub change {
	my($self,$id) = @_;
	my $t2 = Test->new($id);
	$self = $t2; # This line is broke
}