The old wisdom "don't parse HTML with regexes" applies -- use a module instead that does the work for you:

#!/usr/bin/perl
use strict;
use warnings;
use 5.010;
use Mojo::DOM;
my $dom = Mojo::DOM->new('<img class="left" alt="eway-logo" src="/imag
+es/global/logo-eway.gif"> </img>');
$dom->at('img')->attrs({alt => 'new-logo', src => '/images/global/new-
+eway.gif'});
say $dom->to_xml;
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