CAPTCHA files should NOT be copied as are ?

CAPTCHA add-on is great but the instructions a somewhat nuclear:

readme.txt says

1. Unzip and upload all new files to your store directory;
   but it also says
   Use applied files as a sample. All changes of a code are made in brackets
   /> / BOF CAPTCHA
   ... code ...
   // EOF CAPTCHA
   {{ incomplete list of files goes here }}
   which I interpret as "do not overwrite existing files in zen cart but rather manually patch the files based on the differences".

Am I right?

If so, how do I treat files that do not exist (yet) in my template? just copy them over?

Is there better documentation/tutorial to this excellent add-on?

Thanks you, Joe

Files that do not yet exist in your template folder should be copied into it from the stock location.

Are the files listed under the // EOF CAPTCHA different from the files in the Captcha download? If so, I would say that those are intended to be manually patched.
It may also be that that bit is an alternate in case the files have already been changed for another mod - so you can apply the Captcha code to the other version of the file and have both modsworking.

Thank you for your answer. Answering your question, the files listed under the // EOF CAPTCHA are:

/includes/modules/pages/contact_us/header_php.php
/includes/modules/pages/links_submit/header_php.php
/includes/modules/pages/tell_a_friend/header_php.php
/includes/modules/YOUR_TEMPLATE/create_account.php
/includes/templates/YOUR_TEMPLATE/templates/tpl_links_submit_default.php
/includes/templates/YOUR_TEMPLATE/templates/tpl_modules_create_account.php
/includes/templates/YOUR_TEMPLATE/templates/tpl_contact_us_default.php
/includes/templates/YOUR_TEMPLATE/templates/tpl_tell_a_friend_default.php

The files in the captcha download are:

./classes/captcha.php
./languages/english/extra_definitions/captcha.php
./languages/french/extra_definitions/captcha.php
./languages/german/extra_definitions/captcha.php
./modules/pages/contact_us/header_php.php
./modules/pages/links_submit/header_php.php
./modules/pages/product_reviews_write/header_php.php
./modules/pages/tell_a_friend/header_php.php
./modules/YOUR_TEMPLATE/create_account.php
./templates/YOUR_TEMPLATE/buttons/english/button_redraw.gif
./templates/YOUR_TEMPLATE/buttons/english/Thumbs.db
./templates/YOUR_TEMPLATE/buttons/french/button_redraw.gif
./templates/YOUR_TEMPLATE/buttons/french/Thumbs.db
./templates/YOUR_TEMPLATE/templates/tpl_contact_us_default.php
./templates/YOUR_TEMPLATE/templates/tpl_links_submit_default.php
./templates/YOUR_TEMPLATE/templates/tpl_modules_create_account.php
./templates/YOUR_TEMPLATE/templates/tpl_product_reviews_write_default.php
./templates/YOUR_TEMPLATE/templates/tpl_tell_a_friend_default.php

When I used a text compare tool between some of the files in the CAPTCHA package vs. what I have installed (the latest stable Zen Cart), I discovered that some things that are in the latest Zen Cart do not appear in the CAPTCHA version (for example, select TEXT/HTML emails). To me that suggests that only manual, using eye-compare, patching would work.

Would be great if CAPTCHA was part of Zen Cart.