Actually you don't need the backslash escape for the slash if you use a different character for the delimiter.

use strict;
use warnings;

my $test = 'C:\first\second';

print $test, "\n";
$test =~ tr,\\,/,;  

    #$test =~ tr [\\] [/]; 
    #$test =~ tr <\\> </>;
    #$test =~ tr .\\./.;

print $test, "\n";
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