First you can decompose the characters using Unicode::Normalize, then you can use a simple regex to delete all the diacriticals. (I think simply grabbing all the non-spacing mark characters should do it, but there might be an obscure exception or two.)
Here's an example:
use strict;
use warnings;
use utf8;
use Unicode::Normalize;
my $test = "Vous avez aimé l'épée offerte par les elfes à Frodon";
my $decomposed = NFKD( $test );
$decomposed =~ s/\p{NonspacingMark}//g;
print $decomposed;
Output:
Vous avez aime l'epee offerte par les elfes a Frodon