You could either do a global substitution something like
$field =~ s{\n}{ }g to replace any newline with a space or you could achieve the same thing with
split and
join, something like
$field = join q{ }, split m{\n}, $field;. In each case you are going to have to handle a big gap in your line because of the indentation of the second line of the title. However, this post should give you enough clues about
s{this}{the other} to solve that for yourself. Big hint,
\s+ means one or more white-space characters.
Best of luck,
JohnGG