#!/usr/bin/perl
use strict;
use warnings;
use MyApp::Schema;

my $schema = MyApp::Schema->connect('dbi:mysql:database', 'root', '');
my @users = $schema->resultset('User')->all;

# Just traversing the User
foreach my $user (@users) {
    if ($user->email eq 'xyz') {
        $user->password('password');
        $user->update;
    }
}