#!/usr/bin/perl -w

my $raw = 'c:/temp/delete.me';
my $out = 'c:/temp/newfile';
my $lines;
{
    open (RAW, "<$raw") or die "Couldn't open $RAW";
    local $/ = undef;
    $lines = <RAW>;
    close RAW;
}
$lines =~ s/^unwantedstuff//msg;
$lines =~ s/moreunwantedstuff//msg; 
open (OUT, ">$out") or die "Couldn't open $out for writing";
print OUT $lines;
close OUT;