Simply upload the nph-trace.pl file as an ASCII text file to your web server's /cgi-bin (or equivalent) directory.
You may rename the file if you wish, but it's name must begin with "nph-" for this application to run properly. The "nph-" prefix servers as notice to the web server that this application utilizes non-parsed-headers.
IIS 4.0 Users - IIS 4.0 incorrectly handles non-parsed-header scripts. As a workaround, set $UseDoubleHttpHeader to '1' (one) in the script source code. This will cause the HTTP header information to be generated twice, which should solve the immediate problem. Now if only Microsoft could be bothered to test these things before releasing buggy code ... sigh.
All Other Users (including other IIS versions) - Set $UseDoubleHttpHeader to '0' (zero) in the script source code. Setting this value to zero ensures that only one copy of the HTTP headers will be generated.
Note: If, when executing this script, you notice that "HTTP/1.0" and "Content-type" lines are printing at the top of the resulting document, set $UseDoubleHttpHeader to '0' (zero).